Dr. Jeff Masters' WunderBlog

November Atlantic hurricane season outlook

By: JeffMasters, 1:00 PM GMT on October 31, 2008

A small area of disturbed weather in the extreme southern Caribbean has brought heavy rains of up 4-6 inches to Costa Rica and southern Nicaragua over the past two days. This disturbance should persist for the next 3-5 days, and the UKMET and NOGAPS models continue to forecast that a tropical depression could form in this region 4-7 days from now. Steering currents are weak in the area, and any storm forming there would move slowly. Nicaragua would be at greatest risk from such a storm.

Late season Atlantic tropical storms
What are the odds of getting a late-season November or December tropical storm? In the active hurricane period that began in 1995, we've had nine tropical storms in November, and four in December, for an average of one late season storm per year. Six of these late season storms have become hurricanes. The record for late season named storms is four, which occurred in 2005, when three November and one December storm formed. The typical formation location for these late-season storms is the Western Caribbean or the middle Atlantic (Figure 1). The Western Caribbean storms are the most dangerous. There have been two Category 4 hurricanes that have formed in November in that region, Hurricane Lenny of 1999 (the strongest late-season hurricane on record, with 155 mph winds), and Hurricane Michelle of 2001. November storms are primarily a theat to Central America, Cuba, the Cayman Islands, the Bahamas, and the Gulf Coast of Florida.


Figure 1. Historical tropical cyclone tracks in the Atlantic for storms that formed in the first half of November. The Western Caribbean is the preferred formation region.

Sea Surface Temperatures
Sea Surface Temperatures (SSTs) are cooling, but are still warm enough to support a tropical storm over the Caribbean (Figure 1). The Gulf of Mexico will cool significantly in the coming week, due to the presence of cold air and northwesterly winds. It is now too late for the Gulf to spawn a tropical storm, and any hurricane or tropical storm that passes into the Gulf will likely weaken due to the cool SSTs there. The total heat content of the ocean is still high enough to support a major hurricane in the Caribbean.


Figure 2. Sea Surface Temperatures (SSTs) on October 29, 2008. The 26 °C isotherm (red line that separates blue colors from yellow colors) marks the boundary where SSTs are warm enough to support a tropical storm. Image credit: NOAA/AOML.

Wind shear
High wind shear is main reason we don't get many November tropical storms. Wind shear is currently very high north of the Caribbean Sea, and is forecast to remain high for the next two weeks (Figure 3). However, shear is low over the Caribbean, and is forecast to remain low for at least the next two weeks.


Figure 3. Forecast wind shear (in meters per second) for Friday, November 7, at 06 GMT. This is an 8-day forecast generated by the 12Z GMT run of the GFS model on Thursday, October 30. The Caribbean is forecast to remain under low shear for the first half of November, while the U.S. will be protected by very high shear, thanks to the presence of the jet stream.

MJO
We are currently in the phase of the Madden-Julian Oscillation (MJO) that suppresses Atlantic tropical storm formation. The MJO is a pattern of enhanced rainfall that travels along the Equator, and can act to boost hurricane activity when it propagates into the Atlantic. The MJO has a period of about 30-60 days. According to the latest 15-day GFS model forecast and the MJO discussion from the National Weather Service's Climate Prediction Center, we are expected to remain in the inactive phase for the MJO for the next two weeks. By mid-November, we may transition to a positive MJO again. This year, the active phase of the MJO has been strongly correlated with formation of named storms in the Atlantic. Thus, the chances for a late-season named storm may increase by mid-November.

Summary
Given past climatology, warm SSTs in the Caribbean, and forecast low wind shear over the Caribbean for the first half of November, I put the odds at 50% we will see a named storm in the western or south-central Caribbean in the first half of November. Given the recent history of such storms, there is a 50% chance that such a storm would become a hurricane.

I'll update this blog over the weekend if there's any developments in the tropics worth reporting.

For those interested, the portlight.org charity now features a blog that details the recent Hurricane Ike relief effort they undertook.

Jeff Masters

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Honduras, Yemen struggle to recover from tropical cyclones; tropics remain quiet

By: JeffMasters, 1:51 PM GMT on October 29, 2008

Rains have increased in northern Honduras over the past day, with 1-2 inches falling. Additional sporadic heavy rains of 1-2 inches per day are likely over the northern portion of the country through Saturday, as the tail end of a strong cold front interacts with the tropical moisture of the Caribbean. Tropical storm development is not likely in this area due to high wind shear.

The UKMET, NOGAPS, and ECMWF have all been pointing to the possible development of a tropical depression in the south central Caribbean Sea 6-7 days from now, off the coast of Nicaragua. I give a 40% chance that we will see a tropical depression form in the Caribbean 5-10 days from now--the upper level environment looks conducive for tropical cyclone development next week. A tropical wave, currently about 500 miles east of the Lesser Antilles Islands, is under high wind shear and is not a threat to develop.

Honduras struggles to recover from October floods
The situation in Honduras continues to be bad, due to ten days of heavy rains earlier this month from Tropical Depression 16 and a tropical disturbance. The flooding has left 33 dead, 16 missing, 40,000 homeless, and at least $150 million in damage in this impoverished nation of seven million people. The heavy rains this month have also killed seven in Costa Rica, five in Belize, six in Guatemala, four in Nicaragua, and four in El Salvador, for a total of 75 dead or missing.


Figure 1. Total rainfall from Tropical Cyclone 03B. Image credit: NASA TRMM.

Yemen cleans up after Cyclone 03B
In the Middle East, the nation of Yemen continues to recover from Cyclone 03B, which moved ashore October 23 as a tropical depression. Cyclone 03B dumped up to eight inches of rain (Figure 1) on the desert nation, which typically receives only a few inches of rain per year. The deluge from Cyclone 03B created destructive flooding that resulted in at least 180 deaths. The depression had an unusual amount of electrical activity, and nine deaths were due to lightning strikes. The Yemen cyclone is the fourth deadliest tropical cyclone of 2008. The three deadliest were Cyclone Nargis, which killed at least 146,000 people in Myanmar in May; Typhoon Fengshen, which capsized a ferry and killed approximately 1400 people in the Philippines June 19-21; and Hurricane Hanna, which killed 537 people, mostly on Haiti.

October summary of portlight.org Hurricane Ike relief efforts
Beginning balance on October 1, 2008: $11,000
Donations received: $3,800
Total available: $14,900

Expenditures:
Icepilot: $365 (fuel)

Software: $385 (Windows software to better facilitate communication with donors)

Scholarship: $950 to a wheelchair-bound Galveston college student who lost her job at a hotel in Galveston due to the destruction. The scholarship enabled her to finish the semester, which she otherwise would not have been able to do.

Last week's trip: $,(fuel, insurance, crew meals, and lodging enroute (they stayed with and were fed by EmmyRose while there), pizza and drinks for the Saturday meal on the Bolivar Peninsula. This mission delivered over $200,000 in donated supplies.

Supplies: $2,200 (this includes some last minute materials which had been requested but which we couldn't get donated, as well as all the supplies needed to repatriate BillyBadBird to his home place on the Bolivar Peninsula).

Ramps: $1,750 (building materials for reconstruction of ramps at over a dozen disability service organizations)

Salary for Stormjunkie: $1,800. He has put in four 60 hour weeks on this project, plus made two trips to the area. This project couldn't have been done without his hard work.

Total spent in October: $11,350

Remaining balance: $3,550

Escrow: beginning balance: $8,950
Expenditures: $1,500 Legal fees
Remaining funds: $7,450

Support the Portlight Christmas for Gulf Coast Kids Honor Walk
Portlight is sponsoring a new nationwide grassroots event to raise funds for and awareness of their ongoing efforts, specifically to provide Christmas presents (and maybe a big party) for kids and families in devastated Gulf coast areas. Paul Timmons (Presslord) of Portlight has pulled out all the stops in an effort to promote this effort, to the point of posing in woman's clothing. I am supposed to threaten to leave up this truly frightening photo until y'all cough up enough donations to give the people of the hurricane zone a proper Christmas.

Alternatively, committing to a monthly donation--no matter how large or small--will help them build a dependable revenue source, enabling continued operations in the most efficient and effective manner possible. 



I'll have an update Friday (or Thursday, if there's a major development to report). Happy Halloween!

Jeff Masters

Updated: 1:54 PM GMT on October 29, 2008

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Heavy Internet weather

By: JeffMasters, 2:44 PM GMT on October 27, 2008

The tropical Atlantic remains quiet today. There are no threat areas to discuss, and none of our reliable models are calling for tropical storm formation over the next seven days. I'll have a full analysis of what the rest of the hurricane season might bring on Friday. I do think we have one more storm coming this year.

Heavy Internet weather
A record six consecutive tropical storms and hurricanes pounded the U.S. this hurricane season, creating some serious "Internet weather"--a flood of high Internet traffic. On September 12, as Hurricane Ike bore down on the Texas coast, our popular weather web site wunderground.com recorded its busiest day ever--28 million page views, triple its normal traffic. We vaulted from a ranking of 107th to 75th on the Quantcast, Inc. list of most-trafficked web sites in September, thanks to the huge amount of web traffic created by Tropical Storm Fay, Hurricane Gustav, Hurricane Hanna, and Hurricane Ike. As hurricane season winds down, so has our ranking--we're down to 138th on the list of most-trafficked web sites. The ranking will rise again as we enter winter and winter storms begin pounding our population centers.

Historically, hurricanes have caused many Internet-wide bandwidth spikes, as people flocked to weather web sites for the latest advisories. The earliest such spike occurred on August 19, 1991, when Hurricane Bob roared into New England as a Category 2 storm with 100 mph winds. At the time, I was a Ph.D. student working in a University of Michigan weather research lab called MADLAB, run by Professor Perry Samson. Earlier that year, I had written a piece of software called "UM-weather" that allowed anyone at the University to access current weather information using a text-based menu system (this was back before the days of web browsers). The Internet backbone was centered in Ann Arbor and controlled by Merit Networking, Inc. in those days. The networking gurus at Merit showed us how to make "UM-weather" available to anyone on the Internet, and we launched the Internet's first global weather information portal in the summer of 1991. Word quickly spread via email and USENET news groups about this great new real-time Internet weather source. When Hurricane Bob hit, usage of the "UM-weather" service exploded, as tens of thousands of information-hungry Internet users consulted the latest hurricane advisories. "UM-weather" became the most popular service on the entire Internet that day, a position it held for much of 1991 and 1992, according to the experts at Merit. We expanded our educational project over the next few years with the help of National Science Foundation funding, and named it "The Weather Underground"--a tongue-in-cheek reference to the old radical group that also got its start at the University of Michigan.

With the arrival of the World Wide Web and the commercial Internet in 1995, we took our educational project and spun it off into a business. Hurricanes continued to be our biggest draws, and our biggest challenges. It's not easy to design a hardware and software system that can handle a 3x bandwidth spike. Major hurricanes like Fran of 1996 and Floyd of 1999 brought down every major commercial, government, and university weather web site for hours--sometimes days. Since the late 1990s, the industry has figured out how to handle 3x bandwidth spikes, and the days of searching in vain for a working weather web site during a major hurricane event are over.

Top Internet weather web sites as of October, 2008 according to quantcast.com:



Traffic on my blog averages about 50,000 page views per day. The record was on September 12, when 800,000 page views were recorded. Thanks for your support!

I'll have a new blog entry on Wednesday.

Jeff Masters

Updated: 2:51 PM GMT on October 27, 2008

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A quiet weekend in the tropics

By: JeffMasters, 4:23 PM GMT on October 25, 2008

The tropical Atlantic remains quiet today. There are no threat areas to discuss, and none of our reliable models are calling for tropical storm formation over the next seven days. The next area to watch is the Western and Southern Caribbean beginning on Wednesday, when a cold front will stall out over the area and potentially act as a nucleus around which a tropical storm could form. This should give time for flooding to subside in Honduras, where 29 are dead and 14 missing due to recent rains.

Saturday update on the Hurricane Ike portlight.org charity effort
Today, the Portlight truck will be on the hard-hit Bolivar Peninsula. You can follow the mission's progress through a newly set-up web site:

http://www.stormjunkie.com/portlight.php

Today's schedule:

Arrive to pick pizza up around 11:15.
11:30-11:45: begin trip out to Bolivar.
12:30-2:00: Hand out pizza.
1:30-2:00: Tour of Bolivar (will head down to billybadbird's old house).

If the tropics remain quiet on Sunday, my next update will be on Monday morning.

Jeff Masters

Updated: 4:24 PM GMT on October 25, 2008

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Tropical Atlantic quiets down

By: JeffMasters, 2:06 PM GMT on October 24, 2008

The tropical Atlantic is relatively quiet today, though an area of disturbed weather has developed in the extreme southern Caribbean. This disturbance will move westward over Nicaragua and Costa Rica today, bringing heavy rains of 2-4 inches. The heavy rains that have plagued Honduras, northern Guatemala, and Belize in recent days appear likely to take a break today, although a low pressure area still lingers over the Western Caribbean. The death toll now stands at 44 from two weeks of heavy rains triggered by last week's Tropical Depression Sixteen and this week's tropical disturbance 91L. Hardest hit is Honduras, where 23 are dead and some 193,000 persons have been affected. Approximately 23,000 persons were evacuated of which 19,800 are in shelters. More than 340 houses were destroyed and 4,300 were damaged, with 157 roads damaged or destroyed. The past week's flooding has also killed four in Guatemala, seven in Costa Rica, four in Nicaragua, two in Belize, and four in El Salvador.


Figure 1. Total rainfall amounts over Guatemala have been as high as 16 inches over the northern portion of the country the past week. Image credit: Norman E. Avila, climaya.com.

The forecast
Persistent low pressure and sporadic heavy rains will continue over the Western Caribbean for the next ten days. A strong cold front is expected to push southward into the area next Tuesday, and the tail end of this cold front could serve as the nucleus for a new tropical disturbance that will generate another round of very heavy rains for Honduras, northern Guatemala, and Belize late next week. Wind shear is expected to be in the low to medium range over the Western Caribbean next week (Figure 2), so we will need to be concerned with a possible tropical storm forming by the middle of next week along the old front. High wind shear is expected north of the Caribbean during the coming two weeks, and it is unlikely that any tropical storms will be able to affect the U.S. during the coming two weeks--with the possible exception of South Florida. No computer models are forecasting tropical storm development anywhere in the Atlantic over the next seven days.


Figure 2. Forecast wind shear for Monday night Ocober 27, 2008, at 8 pm EDT, as generated by the GFS model with its 00Z run on Friday October 24, 2008. The shear is shown in meters per second (multiply by two to make a rough conversion to knots). Low wind shear (darker red colors) are expected over the Western Caribbean next week, which may allow tropical storm development. Very high wind shear associated with a southern dip in the jet stream will protect the U.S. against any tropical storms that might develop.

Friday update on the Hurricane Ike portlight.org charity effort
A fully packed 26-foot truck loaded with an estimated $200,000 worth of donated goods dropped much of those supplies off yesterday in Bridge City, Texas. Today, the Portlight truck will head to the Chambers County, Texas distribution center between 9:30 and 11:00 am, and drop off the rest of the supplies. These goods will go to residents on the hard-hit Bolivar Peninsula. You can follow the mission's progress through a newly set-up web site:

http://www.stormjunkie.com/portlight.php

On Saturday, from noon to 3 pm CDT, Portlight will be providing a free meal for 400-500 Bolivar Peninsula residents.

I'll have an update Saturday morning.

Jeff Masters

Updated: 3:48 PM GMT on October 24, 2008

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Major flooding disaster continues in Central America

By: JeffMasters, 2:00 PM GMT on October 23, 2008

One of this hurricane season's biggest disasters continues to unfold in Central America, where the death toll now stands at 39 from ten days of heavy rains triggered by last week's Tropical Depression Sixteen and this week's tropical disturbance 91L. At least 10,000 homes have been destroyed and 250,000 people made homeless by the floods. Hardest hit is Honduras, where 23 are dead and 8 missing in flash floods and landslides. Approximately 60% of the nation's roads have been damaged, and the flooding is the worst since Hurricane Mitch of 1998 killed 10,000 people there. The past week's flooding has also killed four in Guatemala, seven in Costa Rica, four in Nicaragua, and four in El Salvador. In Belize, damage is at least $15 million from the floods, and some areas are seeing flooding worse than was experienced during Hurricanes Mitch and Keith. Satellite estimates suggest that up to a foot of rain has fallen over some parts of Central America in the past week. The heavy damage to crops across the region will likely cause severe food shortages in coming months, and substantial international aid will be required.


Figure 1. Current satellite image of the Western Caribbean. Image credit: NOAA.

The forecast
Rains over the hardest hit areas of Central America have eased in the past day, with only 1-2 inches of rain reported. However, visible satellite loops show that heavy thunderstorm activity continues over the Western Caribbean, and has moved into northeast Honduras and Nicaragua this morning. While there is currently little chance that a tropical cyclone will form in the Western Caribbean over the next five days, persistent low pressure and sporadic heavy rains will continue to affect the region. A strong cold front is expected to push southward into the area next Tuesday or Wednesday, and the tail end of this cold front could serve as the nucleus for a new tropical disturbance that will generate another round of very heavy rains for Honduras and Belize late next week.

Elsewhere in the tropics
No computer models are forecasting tropical storm development anywhere in the Atlantic over the next seven days. The National Weather Service office in Houston has posted the storm surge map for Harris County from Ike. It shows a surge of up to 15 feet affected the east side of Houston.

Thursday update on the Hurricane Ike portlight.org charity effort
A fully packed 26-foot truck left yesterday from Charleston, South Carolina, loaded with an estimated $200,000 worth of donated goods for the good citizens of Bridge City, the Bolivar Peninsula, and Houston. You can check out the truck's progress using the streaming video available at http://portlight.camstreams.com/. There's also a chat feature there one can use. The total cost to portlight for this week's charity effort will be approximately $5000-$7000, which will cover truck rental, fuel, lodging, and food. An additional $1750 will be spent for building materials for rebuilding over a dozen ramps for disabilities service organizations, so that clients have access to services. Visit the portlight.org website to engage in the or Stormjunkie's blog for more updates on the effort.

A rough video schedule:

Thursday October 23
Morning: drive to Bridge City, Texas. Noon to 5 pm CDT, unload at Bridge City and Chambers County

Friday October 24
Repatriating WU blogger BillyBadBird to Bolivar Peninsula to begin rebuilding his life there

Saturday October 25
Noon - 3P CDT, free meal for 400-500 Bolivar Peninsula residents


I'll have an update Friday morning.

Jeff Masters

Updated: 2:05 PM GMT on October 23, 2008

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Flooding eases in hard-hit Central America

By: JeffMasters, 1:35 PM GMT on October 22, 2008

The rains over northern Honduras, northern Guatemala, and Belize due to Western Caribbean tropical disturbance 91L have diminished over the past day, with only an additional 1-3 inches of rain falling over the hardest hit areas. River levels have peaked and are now on the decline over most of the affected region (Figure 1). A nationwide state of emergency continues in Honduras, though, where at least thirteen people died in the flooding. In Belize, damage is already estimated in the ten of millions, and some areas are seeing flooding worse than was experienced during Hurricanes Mitch and Keith. In northern Guatemala, at least 70 towns have been cut off by flood waters and a state of emergency has been declared. Satellite estimates suggest that up to a foot of rain has fallen over the region in the past week.


Figure 1. Water level in the Rio Humuya river in northern Honduras this week. The water level rose from three feet to 21 feet as a result of heavy rains from 91L. Image credit: NOAA.

Visible satellite loops show that the intensity and areal coverage of 91L's heavy thunderstorms have diminished significantly over the past day, and the storm is not a threat to develop into a tropical depression. Wind shear is a high 20 knots, and expected to increase over 91L as the storm drifts northwestward over the Yucatan Peninsula today. By Friday, the moisture from 91L should get sucked into an extratropical storm expected to develop in the Gulf of Mexico off the Florida Panhandle's coast. This storm will hit the Panhandle Friday night and Saturday morning, bringing sustained winds of 25-30 mph to the coastal waters, and 1-2 inches of rain.

Elsewhere in the tropics
An area of disturbed weather in association with a tropical wave has developed in the south central Caribbean, a few hundred miles east of the northeast coast of Nicaragua. This region is moving west at 10-15 mph, and is under about 10-20 knots of wind shear. Some slow development is likely before the disturbance comes ashore over northeastern Nicaragua and northeastern Honduras Thursday morning. Heavy rains of 3-6" can be expected in those regions on Thursday, but the disturbance does not have time to develop into a tropical depression. No computer models are forecasting tropical storm development anywhere in the Atlantic over the next seven days.

Wednesday update on the Hurricane Ike portlight.org charity effort
A fully packed 26-foot truck has left today from Charleston, South Carolina, loaded with an estimated $200,000 worth of donated goods for the good citizens of Bridge City, the Bolivar Peninsula, and Houston. I checked out the truck's progress this morning using the streaming video available at http://portlight.camstreams.com/. There's also a chat feature there one can use. The total cost to portlight for this week's charity effort will be approximately $5000-$7000, which will cover truck rental, fuel, lodging, and food. An additional $1750 will be spent for building materials for rebuilding over a dozen ramps for disabilities service organizations, so that clients have access to services. Visit the portlight.org website to engage in the or Stormjunkie's blog for more updates on the effort. It's great to see the wunderground community coming together for this effort!

A rough video schedule:

Wednesday,  October 22
10:30A EDT, arrive FODAC, load DME and other stuff (2 hours), then drive to Biloxi, MS ( 7 hours). Upon arrival there, more supplies will be loaded.

Thursday October 23
Noon to 5P CDT, unloading at Bridge City and Chambers County

Friday October 24
Repatriating WU blogger BillyBadBird to Bolivar Peninsula to begin rebuilding his life there

Saturday  October 25
Noon - 3P CDT, free dinner for 400-500 Bolivar Peninsula residents


I'll have an update Thursday morning.

Jeff Masters

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Heavy rains from 91L kill 11 in Honduras

By: JeffMasters, 1:41 PM GMT on October 21, 2008

A week of heavy rains over northern Honduras, northern Guatemala, and Belize due to Tropical Depression Sixteen and a Western Caribbean tropical disturbance (91L) have resulted in record flooding and deadly mudslides across the region. In Honduras, a nationwide state of emergency has been declared, and at least eleven people are dead and two missing from the flooding. Two large landslides blocked the Coyol River in western Honduras yesterday, forming a lake 500 feet deep. Engineers are attempting to drain the lake today, but they won't be helped by the weather--91L promises to move little the next two days, and will continue to dump heavy rains on the region. In Belize, damage is already estimated in the ten of millions, and some areas are seeing flooding worse than was experienced during Hurricanes Mitch and Keith. In northern Guatemala, at least 70 towns have been cut off by flood waters and a state of emergency has been declared. Satellite estimates (Figure 1) suggest up to a foot of rain has fallen over the region in the past week.


Figure 1. Estimated rainfall for the 6-day period ending at 8pm EDT Monday October 20, 2008. The darker green colors are rains of about 300mm (twelve inches). Image credit: Navy Research Lab, Monterey.

Visible satellite loops show that the intensity and areal coverage of 91L's heavy thunderstorms have remained about the same the past 12 hours, and are primarily affecting Belize and the east coast of Mexico's Yucatan Peninsula this morning. The storm is located too close to land to develop into a tropical depression, and wind shear is also rather high, 20 knots.

The forecast for 91L
Wind shear is expected to remain in the 15-25 knot range over the next three days. Steering currents are weak, and little movement is likely through Wednesday. Heavy rains will affect northern Honduras, northern Guatemala, Belize, Mexico's eastern Yucatan Peninsula, western Cuba, and the Cayman Islands through Wednesday. A trough of low pressure swinging across the Midwest U.S. should be able to start pulling 91L northward or northwestward by Thursday. Once 91L enters the Gulf of Mexico on Thursday, the trough should swing the storm to the northeast, bringing it across the west coast of Florida between Tampa and the Big Bend region on Friday night. Wind shear will be very high over the Gulf of Mexico this week, in the 30-40 knot range, and 91L is expected to make a transition to a very wet extratropical storm by Friday. The storm should bring sustained winds of 30-35 mph and heavy rains of 2-3 inches to Florida.


Figure 2. Latest satellite image of the Western Caribbean disturbance, 91L.

Tuesday update on the portlight.org charity effort
A fully packed 26-foot truck is scheduled to leave Wednesday from Charleston, South Carolina, loaded with an estimated $200,000 worth of donated goods. The total cost to portlight will be approximately $5000-$7000, which will cover truck rental, fuel, lodging, and food. An additional $1750 will be spent for building materials for rebuilding over a dozen ramps for disabilities service organizations, so that clients have access to services. The goods will be delivered to Bridge City, the Bolivar Peninsula, and Houston. Wunderground member EmmyRose is giving the portlight team free room and board for the three days they will be in Texas.

Among the goods that will be delivered to the Hurricane Ike victims:

-Several cases of camping related supplies from Coleman
-$200 worth of supplies donated by Dick's Sporting Goods
-Several cases of socks from Harriss and Covington Hosiery, Inc.
-One pallet of 50 tents
-Several pallets of mens's, women's, and children's pants from Berle Mfg.
-50 manual wheelchairs donated by Cimarron Correctional Institution in Cimarron Correctional Institution in Cushing, Oklahoma, and distributed through Houston Mayors' Office on Disability Affairs
-Medical/surgical/clinical supplies to resuppy several coastal clinics operated by Gateway to Care
-7 manual hospital beds
-12 geriatric chairs on wheels
-Walkers, canes, crutches, bedside commodes
-Wound care supplies and adult diapers
-Several cases of catheters
-Several working powerchairs
-12 pallets of specifically requested supplies courtesy of WalMart
-Under garments from Haynes
-20 cases of garbage bags from Pactiv (Hefty)
-Enough food to feed a meal next Saturday to 400-500 people on Bolivar Peninsula trying to rebuild their lives. Wunderground member Vortfix has generously donated matching funds for this effort, and would like to personally challenge people to help out in a similar fashion.

In addition, the truck is stopping by Biloxi to pick up a host of cleaning supplies, moldicide, insect repellent, etc. from a group which is closing down after three years of post Katrina work.

If you'd like to make a donation to the effort, visit the portlight.org website or Stormjunkie's blog. There will also be a webcam running with live streaming video as events unfold during the trip: http://portlight.camstreams.com/. It's great to see the wunderground community coming together for this effort!

I'll have an update Wednesday morning.

Jeff Masters

Updated: 4:17 PM GMT on October 21, 2008

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Western Caribbean disturbance 91L remaining about the same

By: JeffMasters, 1:47 PM GMT on October 20, 2008

An area of disturbed weather associated with a large area of low pressure (91L) continues to fester off the coast of Belize in the Western Caribbean Sea. This morning's QuickSCAT pass revealed no surface circulation, although some rotation at higher levels of the atmosphere is apparent on satellite loops. The intensity and areal coverage of heavy thunderstorms in the disturbance increased some in the past few hours, spreading over the Cayman Islands. However pressures are not falling at present over the Western Caribbean. Wind shear is a high 20 knots.

The forecast for 91L
Wind shear is expected to remain in the 15-25 knot range over the next four days, which should allow some slow development of the disturbance. Steering currents are weak, and a slow movement west to a point near the Belize coast is possible today through Tuesday. Heavy rains will affect Belize, Mexico's eastern Yucatan Peninsula, and the Cayman Islands through Wednesday. A trough of low pressure swinging across the Midwest U.S. should be able to start pulling 91L northward or northwestward by Wednesday. Once 91L enters the Gulf of Mexico on Thursday, the trough should swing the storm to the northeast, bringing it across the west coast of Florida on Friday or Saturday. Wind shear will be very high over the Gulf of Mexico this week, in the 30-40 knot range, and I doubt 91L would be able to intensify into a hurricane in the face of that kind of shear. The 00Z (8 pm EDT) run of the GFDL model develops 91L into a tropical storm that hits Florida near Sarasota Friday morning with 50 mph winds. The 06Z (2am EDT) run of the GFS model is slower, predicting a landfall near Tampa on Saturday morning. However, this landfall may occur as a weaker subtropical storm or extratropical storm, as predicted by the latest phase space diagrams from Bob Hart at Florida State. The other reliable models do not develop 91L. NHC is giving 91L a medium (20-50% chance) of developing into a tropical depression by Wednesday, which is a reasonable forecast. It currently does not appear that 91L will interfere with the World Series baseball game scheduled to be played Thursday night in St. Petersburg, Florida. Batter up!


Figure 1. Latest satellite image of the Western Caribbean disturbance, 91L.

I'll have an update Tuesday morning.

Jeff Masters

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Western Caribbean disturbance bringing heavy rains to the Yucatan Peninsula

By: JeffMasters, 4:01 PM GMT on October 19, 2008

An area of disturbed weather associated with a large area of low pressure has developed over the Western Caribbean Sea. This is not a reincarnation of Tropical Depression 16, but does have some of the moisture from that storm. The intensity and areal coverage of heavy thunderstorms in the disturbance has slowly increased over the past day (Figure 1). Wind shear is a high 20 knots, and is expected to remain in the 15-25 knot range over the next four days. This may allow some slow development of the disturbance. None of the computer models develop the disturbance, and NHC is giving it a low (<20% chance) of developing into a tropical depression by Tuesday. A slow west-northwestward motion across the Yucatan Peninsula is expected to begin by Wednesday, and the disturbance will bring heavy rains of 3-6 inches to Belize and Mexico's Yucatan over the next three days.


Figure 1. Latest satellite image of the Western Caribbean disturbance. Image credit: NOAA/Satellite Services Division.

I'll have an update Monday morning.

Jeff Masters

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Omar dies, but leaves behind plenty of damage

By: JeffMasters, 3:01 PM GMT on October 18, 2008

Tropical Storm Omar has lost all of its heavy thunderstorm activity, and has been declared dead by NHC. The cleanup continues on those Caribbean islands hit by Omar's rain, wind, storm surge, and high waves, though. Reports from some of the islands to the right of Omar's path indicate that a significant storm surge topped by high battering waves did significant damage to coastal buildings and beaches. The storm's unusual west-to-east motion resulted in storm surge and waves affecting the western side of the islands, which are not as well-defended against these effects. These normally sheltered coastal regions tend to have higher amounts of development, as well. Thankfully, no deaths or injuries have been reported from the storm, which avoided making a direct hit on any islands. The islands should be fully recovered by the time the main tourist season begins in November. Hard hit were:

Dominica
The Office of Disaster Management reports widespread infrastructural damage to roads, sea defenses, ports and utilities from sea swells. The main port was damaged and the Ferry Terminal was extensively damaged. The cruise ship ports were slightly damaged. All barge access for hauling sand and stones were totally destroyed. About 125 people were made homeless by the storm.

St. Vincent and the Grenadines
The western coast of St. Vincent and the Grenadines was severely impacted by swells from Hurricane Omar. Preliminary assessment has indicated widespread flooding, significant erosion, and destruction and damage to coastal property and businesses in the Kingstown areas, Central Leeward, East St. George and the Northern and Southern Grenadines.The Cruise Ship terminal building received significant damage and the businesses housed in the terminal were evacuated. Approximately 20 shops housed in the Bus Terminal in the area of Little Tokyo were destroyed by the battering waves and several others were damaged from the flood waters.

St. Kitts and Nevis
There has been significant coastal damage on the south-western end of the island. Approximately 50 people have been displaced, 30 houses sustained minor damages while nine houses sustained major damages.

Anguilla
Anguillanews.com reports damage to a number of beach front hotels, with many boats grounded.

Antigua
Antigua received 5.71" of rain at the airport, and severe flooding washed out roads and prompted many boat rescues, putting up to 100 people in shelters. Crop damage was heavy, and Prime Minister Baldwin Spencer warned of a produce shortage, saying the farming community "appears to have suffered an extensive loss of crops."

St. Croix
St. Croix, whose eastern tip caught the eyewall winds of Omar, received $700,000 in damage to roads, and had about 40 boats damaged or destroyed in the main harbor. About half of the island's 55,000 people remained with power on Friday, and damage to crops was heavy.


Figure 1. Track of Hurricane Omar. Image credit: reliefweb.org

Elsewhere in the tropics
Heavy rains continue over the Central American nations of Honduras, Nicaragua, Costa Rica, Guatemala, and El Salvador, in association with the remains of Tropical Depression Sixteen. Mudslides and flash flooding have killed three people in Costa Rica and left two more missing, according to ticotimes.net. The remains of TD 16 are expected to remain over land and not regenerate into a tropical storm in either the Atlantic or Pacific.

A small area of heavy thunderstorms is between Jamaica and Haiti, moving west-northwest. This disturbance is under about 15-20 knots of wind shear, is surrounded by dry air, and is too small to develop into a tropical depression over the next two days.

Wind shear is expected to be low over most of the Caribbean during the coming week, and we need to watch the Western Caribbean for tropical storm development. The GFS and Canadian computer models are predicting the development of a tropical depression in the northwestern Caribbean near the western tip of Cuba 5-7 days from now. The other computer models predict that wind shear will be too high in this region to allow a tropical cyclone to develop. If a storm did develop in this region, it would likely move north or northeastward and affect the Gulf Coast of Florida. The likelihood of a tropical storm in the Gulf of Mexico over the next ten days is about 20%, and is about 40% in the Caribbean Sea.

Hurricane Ike relief efforts
There continues to be an urgent need for relief supplies in the wake of Hurricane Ike. I recommend contributions to the portlight.org charity fund, formed by wunderground members to serve the needs of those often bypassed by traditional relief efforts. Contributions are fully tax-deductible, and more details can be found at StormJunkie's blog.

I'll have an update Sunday morning.


Figure 2. Damage to Antigua from Hurricane Omar. Image credit: Iain Mellows.

Jeff Masters

Permalink

Caribbean islands clean up after Omar

By: JeffMasters, 1:56 PM GMT on October 17, 2008

Tropical Storm Omar continues to race northeastward over the open Atlantic Ocean, and is rapidly deteriorating, thanks to high wind shear and cold waters. The storm is only a threat to shipping now, and will not affect any more land areas. The cleanup continues on several Caribbean islands hit by Omar's heavy rains and high winds. Thankfully, no deaths or injuries have been reported from the storm, which avoided making a direct hit on any islands. Hardest hit appears to be the island of Antigua, where 5.71" of rain was recorded at the airport. Severe flooding washed out roads and prompted many boat rescues, putting up to 100 people in shelters. St. Croix, whose eastern tip caught the eyewall winds of Omar, received minor damage, according to media reports. The storm did knock out power to the entire island for nearly a day, and caused considerable damage to piers and boats in the main harbor, though. Flooding was also reported in the British Virgin Islands, St. Martin, and St. Kitts and Nevis. On St. Martin, high waves dumped rocks and sand of the runway of the airport, forcing its closure. The airport was scheduled to be reopened today. More details on Omar's impact on the islands can be found at stormcarib.com.


Figure 1. Hurricane Omar as seen by NASA's Aqua satellite at 17:45 UTC October 15, 2008. At the time, Omar was a Category 1 hurricane with 85 mph winds. Image credit: NASA Earth Observatory.

Elsewhere in the tropics
Several computer models are predicting the development of a tropical depression in the Atlantic's southwestern Caribbean, off the coast of Nicaragua or Honduras, about 5-8 days from now. Wind shear is expected to be low, 5-10 knots, across most of the Caribbean for the next ten days, and I would not be surprised to see a tropical storm develop in the Caribbean next week.

Heavy rains continue over the Central American nations of Honduras, Nicaragua, Costa Rica, Guatemala, and El Salvador, in association with the remains of Tropical Depression Sixteen. The remains of TD 16 could move over the Eastern Pacific and regenerate into a tropical storm. Several of the computer models continue to indicate this possibility, and NHC is giving this system a medium (20-50% chance) of becoming a tropical depression in the Eastern Pacific by Sunday.

Hurricane Ike relief efforts
There continues to be an urgent need for relief supplies in the wake of Hurricane Ike. I recommend contributions to the portlight.org charity fund, formed by wunderground members to serve the needs of those often bypassed by traditional relief efforts. Contributions are fully tax-deductible, and more details can be found at StormJunkie's blog.


Figure 2. Damage in Antigua from Hurricane Omar. Image credit: Iain Mellows.

I'll have an update Saturday morning.

Jeff Masters

Updated: 1:57 PM GMT on October 17, 2008

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Omar intensifies to Category 3, but mostly spares the Lesser Antilles

By: JeffMasters, 2:39 PM GMT on October 16, 2008

Hurricane Omar blasted through the Lesser Antilles last night, intensifying into a Category 3 hurricane as it accelerated to the northeast. Fortunately, the eye missed all the islands, as the storm passed through the narrow Anedega Passage between the Virgin Islands and Anguilla. However, the western eyewall did pass over the eastern tip of St. Croix in the U.S. Virgin Islands (Figure 1), bringing hurricane-force winds there. A Personal Weather Station at the Buccaneer Resort on the northeast coast of St. Croix recorded sustained winds of 80 mph at a height of 110 feet. Rainfall there was 6.28" on Thursday, and 9.11" so far today, for a storm total of 15.39". Other wind measurements and total rainfall for the past two days from Omar:

St. Croix airport 39 mph, gusting to 58 mph, 4.56"
Limetree Bay, south side of St. Croix 51 mph, gusting to 71 mph
Limetree Bay CMAN station, St. Croix 53 mph
St. Maartin airport 45 mph, gusting to 67 mph, 7.02"
Anguilla West End Personal Weather Station 45 mph, gusting to 69 mph, 2.88" (elevation 45 feet)

Buoy 41140 (north side of St. Croix, water depth 85 feet) reported 15 foot waves at the time of eyewall passage. The buoy's anemometer was inoperative.


Figure 1. Radar image of Hurricane Omar as its west eyewall passed over the eastern tip of St. Croix, U.S. Virgin Islands. At the time, Omar was a Category 3 hurricane with 120 mph winds.

Omar in historical perspective
Omar is an unusual hurricane in several respects. It's one of only four hurricanes to affect the Lesser Antilles Islands so late in the season. The only hurricanes that occurred later were the Category 3 1867 hurricane that hit Puerto Rico, and two 1999 storms, Category 2 Jose and famed Category 4 "Wrong-way Lenny". Lenny was the only west-to-east moving hurricane on record to affect the Lesser Antilles. Omar's northeasterly motion is highly unusual as well, and I couldn't find any similar storms in the historical record except Lenny.

Omar is headed out to sea and should not affect any other land areas. Steady weakening is forecast, due to increasing wind shear and cooler sea surface temperatures.


Figure 2. Tracks of all October or later hurricanes to affect the northern Lesser Antilles Islands. Light red tracks indicate a minor hurricane, and dark red tracks are for a major hurricane. Image credit: NOAA Coastal Services Center.

Elsewhere in the tropics
Tropical Depression 16 moved ashore over northern Honduras yesterday and dissipated. However, moisture from the depression remains over the region, which could see additional heavy rains of 2-4 inches today. It is possible that the remains of TD 16 could move over the Eastern Pacific and regenerate into a tropical storm. Both the GFDL and UKMET models have indicated this possibility in recent runs.

No computer models are forecasting tropical cyclone development in the Atlantic over the next seven days.

Hurricane Ike relief efforts
There continues to be an urgent need for relief supplies in the wake of Hurricane Ike. I recommend contributions to the portlight.org charity fund, formed by wunderground members to serve the needs of those often bypassed by traditional relief efforts. Contributions are fully tax-deductible, and more details can be found at StormJunkie's blog.

I'll have an update Friday morning.
Jeff Masters

Updated: 2:46 PM GMT on October 16, 2008

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Omar steadily strengthening

By: JeffMasters, 7:45 PM GMT on October 15, 2008

Hurricane Omar is steadily intensifying as it heads northeast towards an encounter with the Virgin Islands and northern Lesser Antilles early Thursday morning. The latest center fix from the Hurricane Hunters at 3:23 pm EDT put Omar's pressure at 973 mb, a 12 mb drop in six hours, and a drop of 5 mb in just the past two hours. The surface winds measured by the SFMR instrument were in the 85-90 mph range. Omar's current rapid pressure fall will lead to an increase in winds to Category 2 strength late tonight. The Hurricane Hunters noted that the eyewall was open to the southwest, and this is also apparent by examining Puerto Rico radar (Figure 1). Omar is still having trouble with wind shear of 15 knots from the west, and the eye has been visible only intermittently today. It appears that Omar is trying to build a new eyewall inside the current eyewall. It is unlikely Omar will be able to reach Category 3 strength until after this new eyewall is built, a process that will probably not be complete until after the hurricane passes through the islands.


Figure 1. Current radar image of Omar.

The forecast for Omar
There is no change to the forecast track, with the models tightly clustered along a path that would take Omar through the Virgin Islands early Thursday morning. Wind shear is about 15 knots, and is forecast to remain in the moderate 10-20 knot range until landfall. This should allow steady strengthening for the remainder of today. Some dry continental air has arrived on the northwest side of Omar, and I expect that this dry air will begin to penetrate into the vortex by early Thursday morning, slowing down intensification. The latest 12Z (8 am EDT) intensity forecasts from the various models have quite a spread, with the HWRF forecasting a 70 mph tropical storm at landfall; the SHIPS model, a Category 2 hurricane with 100 mph winds; and the GFDL model, a borderline Category 2 or 3 hurricane with winds of 110-115 mph. The official NHC forecast of a Category 2 hurricane at landfall seems like the best compromise. There is about a 20% chance Omar will be a Category 3 hurricane at landfall.

Links to follow
Puerto Rico radar
Eastern Caribbean buoy 42059
San Juan, Puerto Rico weather
St. Croix, Virgin Islands weather
Martinique radar

Tropical Depression 16 off the coast of Honduras
There has been little change to Tropical Depression 16, near the Honduras/Nicaragua border. Satellite loops show that TD 16 is a very large but poorly organized storm, with several far-flung spiral bands that are spreading heavy thunderstorms over a wide area of the Western Caribbean and Central America. The center of circulation is broad and difficult to pin down, but appears to be over the water, within 50 miles of the coast of Honduras.

The forecast for TD 16
The system is expected to track very close to the coast of Honduras, and this proximity to land should limit intensification potential. None of the models are calling for TD 16 to become any stronger than a 40 mph tropical storm. Given the storm's current disorganization, I doubt that it will ever become a tropical storm. However, the depression is going to bring potentially dangerous amounts of rainfall capable of causing flash flooding and mudslides.

Hurricane Ike relief efforts
There continues to be an urgent need for relief supplies in the wake of Hurricane Ike. I recommend contributions to the portlight.org charity fund, formed by wunderground memebrs to serve the needs of those often bypassed by traditional relief efforts. Contributions are fully tax-deductible, and more details can be found at StormJunkie's blog.

Jeff Masters

Updated: 10:31 PM GMT on October 15, 2008

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Virgin Islands brace for Hurricane Omar

By: JeffMasters, 2:24 PM GMT on October 15, 2008

Hurricane Omar is on the move, headed for an encounter with the Virgin Islands and northern Lesser Antilles late tonight and early Thursday morning. Omar is passing very close to Buoy 42059, which measured sustained winds of 58 mph gusting to 72, and 17 foot waves, at 8:50 am EDT. The storm continues to pound the ABC Islands of Aruba, Bonaire, and Curacao with heavy rains. Rainfall amounts of 2-4 inches have been observed over the past three days in these islands, and Netherlands Antilles radar shows that more rain is on the way from Omar's southern spiral band. Rain will be ending early this evening in the ABC Islands, and no significant flooding or damage is likely there.

The latest Hurricane Hunter center fix at 7:30 am EDT found that the pressure has remained nearly constant since yesterday afternoon, 984 mb. The 35-mile diameter eyewall had a gap in it on the south side, and it is apparent that Omar is still struggling with wind shear. Shear was analyzed at 20 knots this morning, which is on the high side of where hurricanes are still able to intensify. Satellite loops show that low level spiral bands and upper level outflow are not present on Omar's west side, due to strong upper level winds from the west creating wind shear on that side of the storm. Outflow and spiral banding are impressive on the other three sides of the storm. A hint of an eye is apparent on visible satellite images. The eye of Omar is now visible on long range radar out of Puerto Rico, and this will be a good way to track the storm until the next Hurricane Hunter flight arrives at 2 pm EDT this afternoon.


Figure 1. Current satellite image of Omar.

The forecast for Omar
The models are tightly clustered along a path that would take Omar through the Virgin Islands late tonight. However, the east coast of Puerto Rico and the islands farther east, such as St. Martin/St. Maartin and Anguilla, are still in the cone of uncertainty, and could get a direct hit. Our main intensity models--the GFDL, HWRF, and SHIPS--all forecast that Omar will be a Category 1 hurricane with winds of 75-85 mph as it passes through the islands. Wind shear is expected to be in the moderate to high range, 15-25 knots, over the next two days, which should allow some modest intensification. I give Omar a 30% chance of reaching Category 2 strength before landfall early Thursday morning, and a 10% chance of being a major Category 3 hurricane.

Omar's storm surge
Wind damage is likely to be the greatest threat from Omar. Storm surge is usually not a problem in the Virgin Islands and northern Lesser Antilles, since these islands are surrounded by deep water, and the surge tends to flow around the islands, rather than be forced up onto the islands. As seen in Figure 2, the maximum storm tide from a mid-strength Category 3 hurricane with 120-125 mph winds is generally in the 3-4 foot range in the Virgin Islands. St. Thomas and Anedega Islands can get a slightly higher surge of 5-6 feet, due to their convex shape facing southwest, which will tend to trap the surge from a northeastward moving hurricane. Since Omar is expected to be a weaker Category 1 or 2 hurricane, maximum storm surge heights of 1-2 feet are expected in the Virgin Islands. The down side of having deep water close to shore is that the waves will be high, and the Virgin Islands and northern Lesser Antilles Islands can expect considerable coastal erosion and damage to coastal structures due to high battering waves.


Figure 2. Expected maximum storm tide (storm surge plus a correction for the storm hitting at high tide) for a Category 3 hurricane moving northeast at 12 mph through the Virgin Islands. This is NOT the surge expected from a particular storm, but rather the maximum computed storm tide (Maximum Envelope of Waters, or MEOW) from eleven different simulated hurricanes (with tracks shown in black with arrows). The simulations were done using NOAA's SLOSH model.

Links to follow
Puerto Rico radar
Eastern Caribbean buoy 42059
San Juan, Puerto Rico weather
St. Croix, Virgin Islands weather
Martinique radar

Tropical Depression 16 off the coast of Honduras
Tropical Depression 16, near the Honduras/Nicaragua border, remains a disorganized heavy rainmaker. Satellite estimates suggest TD 16 has already dumped up to six inches of rain on northern Honduras and Nicaragua, and more heavy rains are on the way for those countries, plus Belize, northern Guatemala, and southern portions of Mexico's Yucatan Peninsula. Satellite loops show that TD 16 is a very large but poorly organized storm, with several far-flung spiral bands that are spreading heavy thunderstorms over a wide area of the Western Caribbean and Central America. The center of circulation is broad and difficult to pin down, but appears to be over the water, within 50 miles of the coast of Honduras.

The forecast for TD 16
The system is expected to track very close to the coast of Honduras, and this proximity to land should limit intensification potential. None of the models are calling for TD 16 to become any stronger than a 40 mph tropical storm. Given the storm's current disorganization, I doubt that it will ever become a tropical storm. However, the depression is going to bring potentially dangerous amounts of rainfall capable of causing flash flooding and mudslides.

Hurricane Ike relief efforts
There continues to be an urgent need for relief supplies in the wake of Hurricane Ike. I recommend contributions to the portlight.org charity fund, formed by wunderground memebrs to serve the needs of those often bypassed by traditional relief efforts. Contributions are fully tax-deductible, and more details can be found at StormJunkie's blog.

I'll have an update this afternoon.

Jeff Masters

Permalink

Omar near hurricane strength; TD 16 slowly strengthening

By: JeffMasters, 7:59 PM GMT on October 14, 2008

Tropical Storm Omar is steadily strengthening as it continues to lash northern Colombia, northern Venezuela, Aruba, Bonaire, and Curacao with heavy rains. The latest Hurricane Hunter center fix at 3:06 pm EDT found the pressure had dropped significantly, to 986 mb. The crew reported that heavy thunderstorms were beginning to wrap around the center, which had taken on a better-defined circular shape. Omar is beginning to form an eyewall, and could be a hurricane by morning. Indeed, surface winds reported by the Hurricane Hunters were 70 mph--very close to hurricane strength. Radar from the Netherlands Antilles shows that the rain has organized into spiral bands, but heavy thunderstorm activity is missing on the northwest side of the storm. Satellite loops show the amount of heavy thunderstorm activity continues to increase and organize. Wind shear has fallen to a moderate 10 knots, allowing this increased organization to occur.


Figure 1. Current satellite image of Omar.

The forecast for Omar
The storm is expected to turn northeastward tonight as an upper-level trough of low pressure digs far enough south to pull the storm towards the Virgin Islands and northern Lesser Antilles Islands. Wind shear is expected to remain in the moderate 10-15 knot range over the next three days, and waters will remain warm, 29°C. This should allow Omar to intensify into a hurricane before it moves through the Virgin Islands and northernmost Lesser Antilles Wednesday night. I expect Omar will remain near its current intensity until it completes building an eyewall, which it should happen between 12 am and 6 am EDT Wednesday. At that time, the potential for rapid intensification into a Category 3 hurricane exists. The latest SHIPS model is forecasting that Omar will rapidly intensify over the next 24 hours, arriving in the Virgin Islands Wednesday evening as a borderline Category 2 or 3 hurricane with 110-115 mph winds. The GFDL and HWRF are much less aggressive. They forecast higher shear affecting Omar, and 70-75 mph winds at landfall. Given Omar's current appearance and rather low pressure, landfall Wednesday evening as a Category 2 hurricane looks like a reasonable intensity forecast. I give Omar a 30% chance of being a major Category 3 hurricane at landfall.

Omar's storm surge
If Omar does become a hurricane, wind damage is likely to be the greatest threat from the storm. Storm surge is usually not a problem in the Virgin Islands and northern Lesser Antilles, since these islands are surrounded by deep water, and the surge tends to flow around the islands, rather than be forced up onto the islands. As seen in Figure 2, the maximum storm tide from a mid-strength Category 3 hurricane with 120-125 mph winds is generally in the 3-4 foot range in the Virgin Islands. St. Thomas and Anedega Islands can get a slightly higher surge of 5-6 feet, due to their convex shape facing southwest, which will tend to trap the surge from a northeastward moving hurricane. The down side of having deep water close to shore is that the waves will be high, and the Virgin Islands and northern Lesser Antilles Islands can expect considerable coastal erosion and damage to coastal structure due to high battering waves.


Figure 2. Expected maximum storm tide (storm surge plus a correction for the storm hitting at high tide) for a Category 3 hurricane moving northeast at 12 mph through the Virgin Islands. This is NOT the surge expected from a particular storm, but rather the maximum computed storm tide (Maximum Envelope of Waters, or MEOW) from eleven different simulated hurricanes (with tracks shown in black with arrows). The simulations were done using NOAA's SLOSH model.

Heavy rains from an outer rain band are just south of Puerto Rico and the Virgin Islands, and will move into the islands over the next few hours. This rain should only last a few hours, and the bulk of Omar's rain will not arrive until Wednesday afternoon. Omar should bring heavy rains of 3-6 inches to the easternmost tip of the Dominican Republic on Wednesday, but the rest of Hispaniola should escape heavy rains. All of the Leeward Islands are at risk of total rainfall of 5-10 inches from Omar. Martinique radar shows heavy rains affecting all of the islands north of Martinique.

Links to follow
Puerto Rico radar
Eastern Caribbean buoy 42059
San Juan, Puerto Rico weather
St. Croix, Virgin Islands weather
Martinique radar

Tropical Depression 16 off the coast of Honduras
Tropical Depression 16, near the Honduras/Nicaragua border, continues to slowly organize. The region is under low wind shear, 5-10 knots. Satellite loops show a modest amount of heavy thunderstorms spread out over a large portion of the Western Caribbean. Heavy rains are affecting extreme northeast Nicaragua and northeastern Honduras, and will be pushing into Belize and Mexico's Yucatan Peninsula this evening. So far, rainfall rates in the heaviest thunderstorms over land have been near 1/2 inch per hour (Figure 3). These rains will steadily increase in coverage and intensity as TD 16 continues to organize. This afternoon's Hurricane Hunter mission found 30-35 mph winds and a central pressure of 1004 mb.

The forecast for TD 16
Conditions are favorable for TD 16 to intensify into a tropical storm. The system is expected to track very coast to the coast of Honduras, and this proximity to land should limit intensification potential. A west-southwesterly motion into the northern coast of Honduras is not expected, since the latest set of model runs keeps TD 16 just offshore. However, it would not take much of a deviation in track for TD 16 to make landfall in northern Honduras. Wind shear is forecast to remain low, 5-10 knots, for the rest of the week. As long as the center remains over water within 50 miles of land, slow intensification should occur, and the GFDL and HWRF models are expecting TD 16 to make landfall Thursday morning in Belize as a 50-55 mph tropical storm. If TD 16 manages to move farther from land, more significant intensification could occur, but that doesn't appear likely at this time.

Links to follow
Puerto Lempira, Honduras weather


Figure 3. Estimated rainfall rates from TD 16 at 9:43 am EDT Tuesday, October 13, 2008. Image credit: Navy Research Lab, Monterey.

Nana and the child of Nana
Tropical Depression Nana has been torn apart by wind shear of 30-40 knots. Regeneration is unlikely due to the continued high wind shear expected along its path. The small area of disturbed weather south-southeast of Nana (90L), has also been disrupted by high wind shear, although latest satelite loops show a small amount of heavy thunderstorm activity still clinging to the east side. The shear should prevent either system from redeveloping.

Hurricane Ike relief efforts: Monday 10/13/08 update
From StormJunkie's blog today: Portlight.org is currently preparing the next push of supplies to head to the forgotten populations and disabilities community along the Texas Gulf Coast. Due to the exceptional pricing that U-haul has given us on trucks we have found the cheapest way to transport these goods is to continue to utilize our U-haul deal to transport these goods. We will be delivering many items to these outlying communities early to mid next week. Look for updates on this trip as it happens!

Some of the supplies that are being delivered include 50 manual wheel chairs that were specifically requested by the Houston Mayor of Disabilities. We have also received items from Coleman and Dick's Sporting goods which will be on the truck. A pallet of tents has also been donated by an anonymous person. Some quantity of socks has also been donated. As we receive and secure more items we will continue to update. In the mean time, if any have connections that may be able to help us acquire some of the following items; your timely help is greatly appreciated.


Figure 4. Chief Dickie Uzzle of the Bridge City Fire Department opening supplies sent by Portlight. Supplies were not only needed but also greatly appreciated.

Contributions to the portlight.org charity fund are fully tax-deductible, and will go to provide relief supplies for those smaller communities typically bypassed by the traditional relief efforts. More details can be found at StormJunkie's blog.

I'll have an update Wednesday morning.

Jeff Masters

Updated: 9:18 PM GMT on October 14, 2008

Permalink

Tropical Storm Omar on the way; Honduras disturbance growing stronger

By: JeffMasters, 1:49 PM GMT on October 14, 2008

Tropical Depression Fifteen is lashing northern Colombia, northern Venezuela, Aruba, Bonaire, and Curacao with heavy rains today, as the storm drifts to the southeast. This morning's 6:35 am EDT QuikSCAT pass saw winds of 45 mph, so this is probably Tropical Storm Omar. An Air Force Hurricane Hunter aircraft will investigate the storm beginning at 2 pm EDT today. Satellite loops show the amount of heavy thunderstorm activity is on the increase, and the cloud pattern is growing more organized. Wind shear has fallen to a moderate 10-15 knots over TD 15, allowing this increased organization to occur. Radar from the Netherlands Antilles shows that the rain has organized into spiral rain bands.


Figure 1. Current satellite image of TD 15.

The track forecast for TD 15
The storm is expected to drift southeastward until an upper-level trough of low pressure swings far enough south tonight to pull the storm northeastward towards Puerto Rico, the Virgin Islands, and the northern Lesser Antilles Islands. Variations in timings between the models have narrowed some, with landfall in the Virgin Islands, northern Lesser Antilles Islands, or eastern Puerto Rico expected sometime between Wednesday afternoon and Wednesday night. Heavy rains should spread into the islands tonight, generating additional rainfall totals of 5-10 inches. The eastern portion of the Dominican Republic will likely get 3-6 inches, and Haiti will escape heavy rains from the storm.


Figure 2. Current radar-estimated rainfall from TD 15.

The intensity forecast for TD 15
Wind shear is expected to remain in the moderate 10-20 knot range over the next two days, and waters will remain warm, 29°C. This should allow TD 15 to intensify into a strong tropical storm with 60-70 mph winds by the time it moves through the Virgin Islands Wednesday evening. The HWRF and GFDL models predict TD 15 will have 65-75 mph sustained winds at landfall Wednesday night.

Links to follow
Puerto Rico radar
Eastern Caribbean buoy 42059
San Juan, Puerto Rico weather

Tropical Depression 16 off the coast of Honduras
Tropical Depression 16, near the Honduras/Nicaragua border, continues to grow more organized. The region is under low wind shear, 5-10 knots. Satellite loops show a large area of heavy thunderstorms that is beginning to take on a spiraling pattern. Heavy rains are affecting extreme northeast Nicaragua and northeastern Honduras.

The forecast for TD 16
Conditions are ripe for TD 16 to intensify into a tropical storm, and a Hurricane Hunter airplane will investigate the storm beginning at 2 pm EDT. The system is expected to track west-northwest today, just off the coast of Honduras. A more west-southwesterly motion may occur tonight and Wednesday, bringing the storm ashore over northern Honduras. Wind shear is forecast to remain low, 5-10 knots, for the rest of the week. As long as the center remains over water more than 50 miles from land and does not stall out, intensification should occur. The system will likely bring 5-10 inches of rain to northern Honduras today through Thursday, potentially causing flash flooding and destructive mudslides. Rain amounts of 2-4 inches are likely today over northeastern Nicaragua and the Cayman Islands. Heavy rains of 4-8 inches will likely affect Belize, northeastern Guatemala, and portions of Mexico's Yucatan Peninsula tonight through Wednesday night. The heaviest rains will stay south of the resort areas of Cancun and Cozumel, though.

It currently appears that the center of TD 16 will stay close enough to the coast that the storm will not grow large and strong enough to tap into the Pacific Ocean as a major source of moisture. However, the counterclockwise flow of air around the storm is already strong enough that it is pulling in air from the Pacific over northern Costa Rica and Nicaragua. This moist flow of air should generate rain amounts of 2-4 inches today along the Pacific coasts of these countries. If 99L were to grow into a strong tropical storm, this moist flow of air would be capable of generating very dangerous rains in the 10-15 inch range along the Pacific coast of Central America.

Links to follow
Puerto Lempira, Honduras weather


Figure 3. Current satellite image of 99L.

Nana and the child of Nana
Tropical Depression Nana has been torn apart by wind shear of 30-40 knots. Regeneration is unlikely due to the continued high wind shear expected along its path. A small area of disturbed weather south-southeast of Nana, near 15N, 41W (90L), has decreased in organization this morning. The circulation of this "child of Nana" is less apparent on this morning's QuikSCAT pass, and the low-level circulation has now been exposed to view, thanks to high wind shear. Nana has pulled her child northward into a region of higher wind shear, and this shear should prevent the 90L from developing any further.


Figure 4. Current satellite image of 90L, the Child of Nana.

Hurricane Ike relief efforts: Monday 10/13/08 update
From StormJunkie's blog today: Portlight.org is currently preparing the next push of supplies to head to the forgotten populations and disabilities community along the Texas Gulf Coast. Due to the exceptional pricing that U-haul has given us on trucks we have found the cheapest way to transport these goods is to continue to utilize our U-haul deal to transport these goods. We will be delivering many items to these outlying communities early to mid next week. Look for updates on this trip as it happens!

Some of the supplies that are being delivered include 50 manual wheel chairs that were specifically requested by the Houston Mayor of Disabilities. We have also received items from Coleman and Dick's Sporting goods which will be on the truck. A pallet of tents has also been donated by an anonymous person. Some quantity of socks has also been donated. As we receive and secure more items we will continue to update. In the mean time, if any have connections that may be able to help us acquire some of the following items; your timely help is greatly appreciated.


Figure 5. Chief Dickie Uzzle of the Bridge City Fire Department opening supplies sent by Portlight. Supplies were not only needed but also greatly appreciated.

Contributions to the portlight.org charity fund are fully tax-deductible, and will go to provide relief supplies for those smaller communities typically bypassed by the traditional relief efforts. More details can be found at StormJunkie's blog.

I'll have an update this afternoon after the Hurricane Hunters have had time to sample today's storms.

Jeff Masters

Updated: 4:03 PM GMT on October 14, 2008

Permalink

Little change to TD 15; new Caribbean distubance gathering strength

By: JeffMasters, 9:10 PM GMT on October 13, 2008

Tropical Depression Fifteen continues to move little as it spins over the Eastern Caribbean, a few hundred miles south of the eastern tip of the Dominican Republic. An Air Force Hurricane Hunter aircraft has just arrived, and found a 1001 mb central pressure at 5:47 pm EDT, and top surface winds of 35-40 mph. Eastern Caribbean buoy 42059 is in the heavy thunderstorm region to the east of TD 15's center, and recorded sustained winds of 20-25 mph this afternoon. Satellite loops show the amount of heavy thunderstorm activity has decreased some this afternoon. However, the heaviest thunderstorms now lie very close to the center of circulation, a sign the storm is getting more organized. Wind shear has fallen to a moderate 10-15 knots over TD 15, allowing this increased organization to occur. Radar from Puerto Rico and the Netherlands Antilles shows that the rain area is poorly organized, with no spiral rain bands evident. Dominican Republic radar was down this afternoon.


Figure 1. Current satellite image of TD 15.

The track forecast for TD 15
The storm is expected to move little through Tuesday afternoon. An upper-level trough of low pressure is forecast to position itself to the north of Puerto Rico by Tuesday afternoon, and the counter-clockwise flow of air around this trough should draw TD 15 to the northeast across Puerto Rico, the Virgin Islands, or the eastern Dominican Republic on Wednesday or Thursday. There are considerable timing variations between the models. The fastest model is the GFDL, which predicts a Wednesday morning landfall in Puerto Rico. The slower NOGAPS and UKMET models predict a Thursday morning landfall. If a Wednesday landfall occurs, it would probably be as a tropical storm with 50-60 mph winds. A landfall delayed until Thursday would allow a stronger storm to develop, and TD 15 could be a Category 1 hurricane in this case. Up to five inches of rain has already fallen over the Virgin Islands and eastern Puerto Rico (Figure 2), but the heaviest rains have retreated to the south for the time being. Heavy rains are likely to develop over these islands again on Tuesday, and move into the eastern Dominican Republic and the northern Lesser Antilles Islands. Additional rain amounts of 5-10 inches are likely over some of these regions. Over Puerto Rico, isolated rain amounts in excess of 20 inches are possible before the storm clears the islands by Thursday. It currently appears that Haiti will only get 1-2 inches of rain from TD 15.


Figure 2. Current radar-estimated rainfall from TD 15.

The intensity forecast for TD 15
Wind shear is expected to remain in the moderate 10-20 knot range over the next three days, and waters will remain warm, 29°C. This should allow TD 15 to intensify into a tropical storm by Tuesday. The HWRF and GFDL models both intensify TD 15 into a Category 1 hurricane before it hits Puerto Rico on Wednesday. This seems overly aggressive, given the moderate 10-20 knots of wind shear expected. I'm expecting Thursday will be the earliest that TD 15 will become a hurricane.

Links to follow
Puerto Rico radar
Eastern Caribbean buoy 42059
San Juan, Puerto Rico weather

Disturbance 99L off the coast of Nicaragua
An area of disturbed weather (99L) has formed in the Southwest Caribbean, off the coast of Nicaragua. An ASCAT pass from 11:28 am EDT showed a circulation center developing near 14N 83W, about 100 miles offshore from Puerto Cabeza, Nicaragua. The pressure there was 1005 mb and falling at 3 pm EDT today. The region is under low wind shear, 5-10 knots. Satellite loops show a moderate area of heavy thunderstorms that is increasing in areal coverage and intensity. Heavy rain has moved into extreme northeast Nicaragua and northeastern Honduras.

The forecast for 99L
Most of the models forecast development of a tropical depression in this region by Wednesday. The system is expected to track northwest, just off the coast of Central America, until Tuesday afternoon. On Tuesday, a ridge of high pressure is expected to build in, forcing 99L to the west. It currently appears that the center of 99L will remain over water, which should allow the storm to intensify into a tropical storm by Wednesday. Wind shear is forecast to remain low, 5-10 knots, for the rest of the week. As long as the center remains over water more than 50 miles from land and does not stall out, intensification should occur. The system will likely bring 5-10 inches of rain to northern Honduras tonight through Thursday, potentially causing flash flooding and destructive mudslides. Heavy rains may also spread over the Cayman Islands on Tuesday afternoon. It is 40% likely that the counterclockwise flow of air around the storm will grow large and strong enough to tap the Pacific Ocean as a source of moisture, triggering very heavy rains of 10-15 inches along the Pacific coasts of northern Costa Rica and Nicaragua Tuesday through Thursday. Rains of this magnitude are capable of causing severe flooding and life-threatening mudslides. By Thursday, 99L could be as far west as Belize (as forecast by the GFDL model), or wandering erratically in the Western Caribbean (as forecast by the NOGAPS model). Heavy rains will likely begin affecting Belize, northern Guatemala, and Mexico's Yucatan Peninsula beginning on Wednesday. If the storm is large enough, if will also bring heavy rains to the Pacific coasts of Honduras and El Salvador beginning on Wednesday. No models are currently forecasting a threat to the U.S. in the coming seven days from 99L.


Figure 3. Current satellite image of 99L.

Nana and the child of Nana
Tropical Depression Nana, over the middle Atlantic Ocean, is being torn apart by wind shear of 30-40 knots. A small vortex near 13N, 42W (90L) that was part of the original disturbance that developed into Nana, has developed its own cluster of heavy thunderstorms. The circulation of this "child of Nana" is apparent on this morning's ASCAT pass, which noted top winds of 25 mph on the south side. The child of Nana is south of the region of high wind shear affecting Nana, in a region where the shear is only 5-10 knots. Nana should be able to pull its child northwestward into the higher shear region on Tuesday, but this may be enough time for the child of Nana to develop into a tropical depression.


Figure 4. Current satellite image of 90L, the Child of Nana.

Hurricane Ike relief efforts: Monday 10/13/08 update
From StormJunkie's blog today: Portlight.org is currently preparing the next push of supplies to head to the forgotten populations and disabilities community along the Texas Gulf Coast. Due to the exceptional pricing that U-haul has given us on trucks we have found the cheapest way to transport these goods is to continue to utilize our U-haul deal to transport these goods. We will be delivering many items to these outlying communities early to mid next week. Look for updates on this trip as it happens!

Some of the supplies that are being delivered include 50 manual wheel chairs that were specifically requested by the Houston Mayor of Disabilities. We have also received items from Coleman and Dick's Sporting goods which will be on the truck. A pallet of tents has also been donated by an anonymous person. Some quantity of socks has also been donated. As we receive and secure more items we will continue to update. In the mean time, if any have connections that may be able to help us acquire some of the following items; your timely help is greatly appreciated.


Figure 5. These are the supplies that were shipped.

Contributions to the portlight.org charity fund are fully tax-deductible, and will go to provide relief supplies for those smaller communities typically bypassed by the traditional relief efforts. More details can be found at StormJunkie's blog.

Jeff Masters

Updated: 10:26 PM GMT on October 13, 2008

Permalink

Tropical Depression 15 forms; new Caribbean disturance a threat to develop

By: JeffMasters, 2:58 PM GMT on October 13, 2008

Tropical Depression Fifteen has formed this morning, and is already bringing flooding rains to the Virgin Islands and Puerto Rico. This morning's QuikSCAT pass showed a well-defined closed surface circulation, but did not scan the eastern portion of the storm, where the heaviest thunderstorms are. Eastern Caribbean buoy 42059 is in the heavy thunderstorm region to the east of 98L's center, and winds there were sustained at 20-26 mph this morning. Satellite loops show an impressive amount of heavy thunderstorm activity that is increasing in intensity and coverage. Wind shear is a high 20 knots over the disturbance, due to strong upper level winds out of the west. These strong winds are keeping 98L's heavy thunderstorms pushed over to the east side of the center of circulation. The storm is a little too far from Puerto Rico radar to see rotation of the rain. The rain area is poorly organized, with no spiral rain bands evident. However, radar from the Netherlands Antilles does show spiral bands beginning to develop on the south side of the depression. Dominican Republic radar was down this morning.


Figure 1. Current satellite image of TD 15. Image credit: NOAA.


Figure 2. Current radar-estimated rainfall from 98L.

The track forecast for TD 15
The storm is drifting slowly northwestward, and this motion is expected to continue through Tuesday. A upper-level trough of low pressure is forecast to position itself to the north of Puerto Rico by Tuesday. The counter-clockwise flow of air around this trough should draw TD 15 to the northeast across Puerto Rico or the eastern Dominican Republic on Wednesday. Up to five inches of rain has already fallen over the Virgin Islands and eastern Puerto Rico (Figure 2), and additional heavy rains of 5-10 inches are likely over these islands through tonight. Heavy rains of 5-10 inches per day will likely spread to the eastern Dominican Republic and the northern Lesser Antilles Islands by Tuesday morning, and continue through Wednesday night. Over Puerto Rico, isolated rain amounts in excess of 20 inches are possible before the storm clears the islands by Thursday. It currently appears that Haiti will only get 1-3 inches of rain from TD 15.

The intensity forecast for TD 15
Wind shear is expected to fall to the moderate 10-20 knot range over the next three days, and waters will remain warm, 29°C. This should allow 98L to intensify into a tropical storm by Tuesday. The HWRF and GFDL models both intensify TD 15 into a hurricane before it hits Puerto Rico on Wednesday. This seems overly aggressive, given the moderate 10-20 knots of wind shear expected. The SHIPS model forecast and official NHC forecast of a strong tropical storm hitting the island on Wednesday is more reasonable. A Hurricane Hunter aircraft will investigate the storm this afternoon.

Links to follow
Puerto Rico radar
Eastern Caribbean buoy 42059
San Juan, Puerto Rico weather

Nana
Tropical Storm Nana, the fourteenth named storm of this busy Atlantic hurricane season, formed yesterday over the middle Atlantic Ocean. Nana is one of those "blink and you'll miss it" storms, as high wind shear of 30 knots is in the process of tearing the storm apart. The UKMET model did a nice job forecasting the development of this storm, up to a week in advance.

New disturbance in the Southwest Caribbean (99L)
An area of disturbed weather (99L) has formed in the Southwest Caribbean, off the coast of Nicaragua. The region is under a low to moderate amount of wind shear, 5-15 knots. The NOGAPS model forecasts the development of a tropical depression in this region by Thursday. The model predicts the storm will move northwest and threaten Honduras, the Cayman Islands, the Yucatan Peninsula, and western Cuba by early next week. I put the odds a tropical depression forming in this region by Wednesday in the moderate range (20-50%).

Saturday's update on Hurricane Ike relief efforts
I got this very nice email Friday, giving appreciation for all those who helped out through the portlight.org Hurricane Ike charity effort:


I just wanted to express my sincere gratitude, on behalf of the City of Houston, the Mayor, and our community partners over at TIRR/Memorial Hermann, for all of your involvement in bringing medical supplies and equipment together to help Texans with disabilities affected by Hurricane Ike. I can't tell you how much we all appreciate the fact that you so quickly mobilized and leveraged such a tremendous amount of support to bring these needed items to Houston and other Texas cities.

An email simply doesn't do justice to the generous spirit and initiative that you, Paul Timmons, and your partners took to make this happen, nor to our gratitude. However, I just want you to know that we think about you all in appreciation every single day over here, and there are many who are directly benefiting from your generosity.

By the way, Paul Timmons mentioned that it looks like another shipment of 30-50 wheelchairs can be sent over here. All I can say is wow! Thank you for not forgetting about us, and for realizing that we still have a lot of needs here that we are trying to meet - even 4 weeks after the hurricane.

Again, please accept my sincere thanks. I hope that you have a wonderful weekend!

Michelle Colvard, MPH
Executive Director
Mayor's Office for People with Disabilities

Contributions to this highly worthy portlight.org charity fund are fully tax-deductible, and will go to provide relief supplies for those smaller communities typically bypassed by the traditional relief efforts. More details can be found at StormJunkie's blog.

I'll have an update this afternoon, between 3pm-4:30pm EDT.
Jeff Masters

Permalink

Dangerous Eastern Caribbean disturbance near tropical depression strength

By: JeffMasters, 1:50 PM GMT on October 13, 2008

A very vigorous and potentially dangerous tropical disturbance (98L) is approaching tropical depression strength over the eastern Caribbean, a few hundred miles south of the eastern tip of the Dominican Republic. This morning's QuikSCAT pass showed a well-defined closed surface circulation, but did not scan the eastern portion of the storm, where the heaviest thunderstorms are. Eastern Caribbean buoy 42059 is in the heavy thunderstorm region to the east of 98L's center, and winds there were sustained at 20-26 mph this morning. Satellite loops show an impressive amount of heavy thunderstorm activity that is increasing in intensity and coverage. Wind shear is a high 20 knots over the disturbance, due to strong upper level winds out of the west. These strong winds are keeping 98L's heavy thunderstorms pushed over to the east side of the center of circulation. The storm is a little too far from Puerto Rico radar to see rotation of the rain. The rain area is poorly organized, with no spiral rain bands evident. Dominican Republic radar was down this morning.


Figure 1. Current satellite image of 98L.


Figure 2. Current radar-estimated rainfall from 98L.

The track forecast for 98L
The storm is drifting slowly west-northwestward, and this motion is expected to continue through Tuesday. An upper-level low pressure system is expected to separate from the jet stream and park itself to the north of Puerto Rico by Tuesday. The counter-clockwise flow of air around this low should draw 98L to the northeast across Puerto Rico or the Dominican Republic by Wednesday. Up to five inches of rain has already fallen over the Virgin Islands and eastern Puerto Rico (Figure 2), and additional heavy rains of 5-10 inches are likely over these islands through tonight. Heavy rains of 5-10 inches per day will likely spread to the eastern Dominican Republic and the northern Lesser Antilles Islands by Tuesday morning, and continue through Wednesday night. Over Puerto Rico, isolated rain amounts in excess of 20 inches are possible before the storm clears the islands by Thursday. It currently appears that Haiti will only get 1-3 inches of rain from 98L, but this forecast could change if the storm progresses father west than expected.

The intensity forecast for 98L
Wind shear is expected to fall to the moderate 10-20 knot range over the next three days, and waters will remain warm, 29°C. This should allow 98L to intensify into a tropical storm by Tuesday. The HWRF and GFDL models both intensify 98L into a hurricane before it hits Puerto Rico on Wednesday. This seems overly aggressive, given the moderate 10-20 knots of wind shear expected. The SHIPS model forecast of a strong tropical storm on Wednesday is more reasonable. NHC is giving 98L a high (>50% chance) of developing into a tropical depression by Wednesday. A Hurricane Hunter aircraft will investigate the storm this afternoon.

Links to follow
Puerto Rico radar
Eastern Caribbean buoy 42059
San Juan, Puerto Rico weather

Nana
Tropical Storm Nana, the fourteenth named storm of this busy Atlantic hurricane season, formed yesterday over the middle Atlantic Ocean. Nana is one of those "blink and you'll miss it" storms, as high wind shear of 30 knots is in the process of tearing the storm apart. The UKMET model did a nice job forecasting the development of this storm, up to a week in advance.

New disturbance in the Southwest Caribbean
An area of disturbed weather has formed in the Southwest Caribbean, from the Cayman Islands southwards to Costa Rica. The region is under a low to moderate amount of wind shear, 5-15 knots. The NOGAPS model forecasts the development of a tropical depression in this region by Thursday. The model predicts the storm will move northwest and threaten Jamaica, the Cayman Islands, and western Cuba by early next week. I put odds a tropical depression forming in this region by Friday at moderate (20-50%).

Saturday's update on Hurricane Ike relief efforts
I got this very nice email Friday, giving appreciation for all those who helped out through the portlight.org Hurricane Ike charity effort:


I just wanted to express my sincere gratitude, on behalf of the City of Houston, the Mayor, and our community partners over at TIRR/Memorial Hermann, for all of your involvement in bringing medical supplies and equipment together to help Texans with disabilities affected by Hurricane Ike. I can't tell you how much we all appreciate the fact that you so quickly mobilized and leveraged such a tremendous amount of support to bring these needed items to Houston and other Texas cities.

An email simply doesn't do justice to the generous spirit and initiative that you, Paul Timmons, and your partners took to make this happen, nor to our gratitude. However, I just want you to know that we think about you all in appreciation every single day over here, and there are many who are directly benefiting from your generosity.

By the way, Paul Timmons mentioned that it looks like another shipment of 30-50 wheelchairs can be sent over here. All I can say is wow! Thank you for not forgetting about us, and for realizing that we still have a lot of needs here that we are trying to meet - even 4 weeks after the hurricane.

Again, please accept my sincere thanks. I hope that you have a wonderful weekend!

Michelle Colvard, MPH
Executive Director
Mayor's Office for People with Disabilities

Contributions to this highly worthy portlight.org charity fund are fully tax-deductible, and will go to provide relief supplies for those smaller communities typically bypassed by the traditional relief efforts. More details can be found at StormJunkie's blog.

I'll have an update this afternoon.
Jeff Masters

Updated: 1:58 PM GMT on October 13, 2008

Permalink

Puerto Rico and Hispaniola will get heavy rains from 98L

By: JeffMasters, 4:53 PM GMT on October 12, 2008

A large region of low pressure (98L) has developed over the eastern Caribbean, a few hundred miles south of Puerto Rico. Wind shear is a high 20-25 knots over the disturbance, but waters are warm, about 29° C. This morning's QuikSCAT pass showed no closed surface circulation. Top winds seen by QuikSCAT were about 30 mph. The amount of heavy thunderstorm activity is moderate and increasing. At 3 pm EDT, visible satellite loops showed signs that a low level surface circulation may be starting to form near 15N 67.5W, about 200 miles south of the Mona Passage between Puerto Rico and the Dominican Republic.


Figure 1. Current satellite image of 98L.

The forecast for 98L
Wind shear is expected to fall to the moderate 15-20 knot range the next three days, and waters will remain warm, 29°C. This should allow 98L to slowly organize and approach tropical depression status 1-2 days from now. The UKMET, NOGAPS, and ECMWF models all indicate the 98L will come close to developing into a tropical depression by Wednesday, when it is expected to be near or over Hispaniola or Puerto Rico. The HWRF forecasts that 98L will organize into a tropical storm that will hit Puerto Rico Tuesday morning. Puerto Rico, the Dominican Republic, and the Virgin Islands are likely to receive heavy rains of 4-8 inches, with isolated amounts of 12 inches, during the period Monday through Thursday.

An upper-level low pressure system is expected to separate from the jet stream and park itself to the north of Puerto Rico by Tuesday. The counter-clockwise flow of air around this low should draw 98L to the north across Puerto Rico and Hispaniola by Wednesday. NHC is giving 97L a medium (20-50% chance) of developing into a tropical depression by Tuesday.

97L
An area of disturbed weather (97L) midway between Africa and the Lesser Antilles Islands has developed a well-organized closed circulation. However, wind shear of 30 knots is allowing just a small amount of heavy thunderstorm activity to cling to the east side of the storm. This morning's QuikSCAT pass saw winds of 40-45 mph in these heavy thunderstorms. Satellite loops show the classic signature of a tropical cyclone under high wind shear--a low level circulation center exposed to view, with a clump of heavy thunderstorms on the side away from where strong upper-level winds are blowing.


Figure 2. Current satellite image of 97L.

The forecast for 97L
There is a chance shear may relax a little this afternoon, which may allow enough heavy thunderstorm activity to build and convince NHC to call this system Tropical Storm Nana. Wind shear is expected to rise to the high 35-40 knot range Monday and Tuesday, which should prevent any further development. NHC is giving 97L a high (>50% chance) of developing into a tropical depression by Tuesday.

Elsewhere in the Atlantic
Most of the models continue to forecast the possible development of a tropical depression in the south central Caribbean, off the coast of Nicaragua, 5-7 days from now.


Figure 3. Hurricane Norbert over the Gulf of California at 23:45 GMT Saturday October 11, 2008. At the time, Norbert was a Category 1 hurricane with 85 mph winds. Tropical Storm Odile is visible at lower right. Image credit: NASA Goddard.

Norbert
Hurricane Norbert made landfall on the west coast of Mexico's Baja Peninsula Saturday afternoon as a Category 2 hurricane with 105 mph winds. Norbert crossed Baja and the Gulf of California, making a second landfall on mainland Mexico as a Category 1 hurricane with 85 mph winds. Norbert made landfall along a sparsely populated stretch of the coast about 145 miles northwest of the resort town of Cabo San Lucas. The storm tore off roofs and flooded homes knee-deep in the town of Puerto San Carlos, near where the eye came ashore. The remains of Norbert are expected to slosh into the Midwestern U.S. on Monday and combine with an area of low pressure over Kansas. The resulting storm could trigger rains in excess of seven inches, according to the latest forecast from NOAA's Hydrometeorological Prediction Center (Figure 4).


Figure 4. Forecast rain amounts for the five-day period ending Friday, October 17, 2008. Image credit: NOAA/HPC.

Saturday's update on Hurricane Ike relief efforts
I got this very nice email yesterday, giving appreciation for all those who helped out through the portlight.org Hurricane Ike charity effort:


I just wanted to express my sincere gratitude, on behalf of the City of Houston, the Mayor, and our community partners over at TIRR/Memorial Hermann, for all of your involvement in bringing medical supplies and equipment together to help Texans with disabilities affected by Hurricane Ike. I can't tell you how much we all appreciate the fact that you so quickly mobilized and leveraged such a tremendous amount of support to bring these needed items to Houston and other Texas cities.

An email simply doesn't do justice to the generous spirit and initiative that you, Paul Timmons, and your partners took to make this happen, nor to our gratitude. However, I just want you to know that we think about you all in appreciation every single day over here, and there are many who are directly benefiting from your generosity.

By the way, Paul Timmons mentioned that it looks like another shipment of 30-50 wheelchairs can be sent over here. All I can say is wow! Thank you for not forgetting about us, and for realizing that we still have a lot of needs here that we are trying to meet - even 4 weeks after the hurricane.

Again, please accept my sincere thanks. I hope that you have a wonderful weekend!

Michelle Colvard, MPH
Executive Director
Mayor's Office for People with Disabilities

Contributions to this highly worthy portlight.org charity fund are fully tax-deductible, and will go to provide relief supplies for those smaller communities typically bypassed by the traditional relief efforts. More details can be found at StormJunkie's blog.

Jeff Masters

Updated: 7:42 PM GMT on October 12, 2008

Permalink

Norbert pounds Baja

By: JeffMasters, 4:24 PM GMT on October 11, 2008

An area of disturbed weather (97L) midway between Africa and the Lesser Antilles Islands continues to slowly organize. Wind shear is a moderate 10-15 knots over the disturbance, and waters are warm, about 29° C. Satellite loops and this morning's QuikSCAT pass show that two circulations have developed, one near 10N 44W, and the other 400 miles to the northeast, near 13N 37W. Both circulations are elongated and disorganized. Top winds were about 35 mph.


Figure 1. Current satellite image of 97L.

The forecast for 97L
Wind shear is expected to remain in the moderate 15-20 knot range the next three days, and waters will remain warm, 28-29°C. This should allow 97L to come close to tropical depression status two days from now. The fact that there are two circulations competing for the same energy and moisture will slow down development. The larger circulation near 13N 37W will probably become the dominant one. The UKMET and NOGAPS models develop 97L into a tropical depression by Tuesday. NHC is giving 97L a medium (20-50% chance) of developing into a tropical depression by Monday. The storm is expected to track to the northwest over the open Atlantic, and shouldn't affect any land areas. By Wednesday, most of the models are predicting that an extratropical storm will form just north of Puerto Rico, and this storm will probably weaken 97L by bringing high wind shear.

Elsewhere in the Atlantic
Most of the models continue to forecast the possible development of a tropical depression in the south central Caribbean, off the coast of Nicaragua, 5-7 days from now. I put the odds of a tropical storm forming in the Caribbean next week at 30%. The potential motion of such a storm is difficult to predict at this time.

Hurricane Norbert pounds Baja
Hurricane Norbert has made landfall on the west coast of Mexico's Baja Peninsula. Norbert was briefly a Category 3 hurricane this morning, but high wind shear has stretched the storm and opened up the eye, weakening Norbert to an upper-end Category 2 hurricane with 105 mph winds. Given that no Category 3 hurricane has hit the west coast of Baja since record keeping began in 1949, Norbert may be the strongest hurricane on record to hit the west coast of Baja (two Category 3 hurricanes have hit the east coast of Baja). Exceptionally warm water temperatures of 1-3°C above average helped Norbert remain strong right up until landfall.

Crossing rugged Baja will probably knock Norbert down a full Category, by about 20-25 mph. The storm will still be a Category 1 hurricane when it makes it second landfall on mainland Mexico north of Los Mochis. The Hurricane Hunters are scheduled to fly into Norbert this afternoon to see how intense this second Mexican landfall will be. Rainfall amounts in mainland Mexico will be 4-8 inches, and 6-10 inches over Baja. Norbert's remains should bring 1-2 inches of rain to portions of western Texas and southeastern New Mexico. Since Norbert is so strong and fast-moving, it may be able to carry an unusual amount of moisture deep into the Midwestern U.S. by Monday. This could lead to flooding problems in Kansas and surrounding states early next week. A similar situation occurred in 1983, when Category 4 Hurricane Tico hit Mexico. Moisture from Tico would up in Oklahoma, where up to 16 inches of rain fell (Figure 2). The resulting flooding caused about $100 million in damage. The latest 5-day rain forecast from NOAA's Hydrometeorological Prediction Center (Figure 3) shows that the moisture from Norbert is expected to trigger heavy rains of up to three inches over Kansas and Nebraska over the next five days. This is probably an underestimate, and rainfall amounts in the 4-6 inch range are likely over Kansas and Nebraska over the coming week.

Links to follow:
Mexican radar
Loreto, Mexico weather
Santa Rosalia, Mexico weather


Figure 2. Total rain amounts from Hurricane Tico of 1983. Image credit: NOAA.


Figure 3. Forecast rain amounts for the five-day period ending Thursday, October 16, 2008. Image credit: NOAA/HPC.

Odile dumping heavy rains on Mexico
Mexico has another storm to be concerned with, Tropical Storm Odile. Satellite estimates indicate Odile has dumped up to six inches of rain on the coast just east of Acapulco. Additional heavy rains of up to eight inches should affect the coast as Odile tracks along the coast, just offshore. The storm's location and intensity are difficult to gauge via infrared satellite loops, and we'll have to wait until the Hurricane Hunters arrive this afternoon before we have a good idea of Odile's strength. Odile is under about 10-15 knots of wind shear, and this shear is forecast to remain in the 15-20 knot range the next 3-5 days. This should allow the storm to gradually intensify into a Category 1 hurricane.

Saturday update on Hurricane Ike relief efforts
I got this very nice email yesterday, giving appreciation for all those who helped out through the portlight.org Hurricane Ike charity effort:


I just wanted to express my sincere gratitude, on behalf of the City of Houston, the Mayor, and our community partners over at TIRR/Memorial Hermann, for all of your involvement in bringing medical supplies and equipment together to help Texans with disabilities affected by Hurricane Ike. I can't tell you how much we all appreciate the fact that you so quickly mobilized and leveraged such a tremendous amount of support to bring these needed items to Houston and other Texas cities.

An email simply doesn't do justice to the generous spirit and initiative that you, Paul Timmons, and your partners took to make this happen, nor to our gratitude. However, I just want you to know that we think about you all in appreciation every single day over here, and there are many who are directly benefiting from your generosity.

By the way, Paul Timmons mentioned that it looks like another shipment of 30-50 wheelchairs can be sent over here. All I can say is wow! Thank you for not forgetting about us, and for realizing that we still have a lot of needs here that we are trying to meet - even 4 weeks after the hurricane.

Again, please accept my sincere thanks. I hope that you have a wonderful
weekend!

Michelle Colvard, MPH
Executive Director
Mayor's Office for People with Disabilities

Contributions to this highly worthy portlight.org charity fund are fully tax-deductible, and will go to provide relief supplies for those smaller communities typically bypassed by the traditional relief efforts. More details can be found at StormJunkie's blog.

Jeff Masters

Updated: 4:27 PM GMT on October 11, 2008

Permalink

Norbert re-strengthens; Odile dumping heavy rains; Atlantic getting more active

By: JeffMasters, 2:13 PM GMT on October 10, 2008

An area of disturbed weather (97L) has developed midway between Africa and the Lesser Antilles Islands. Wind shear is a moderate 10-15 knots over the disturbance, and waters are warm, about 29° C. Satellite loops show a large area of heavy thunderstorms that are beginning to look organized, with a little bit of upper-level outflow to the north. This morning's QuikSCAT pass mostly missed 97L, but did show an elongated, poorly organized surface circulation developing, and 20 mph winds.


Figure 1. Current satellite image of 97L.

The forecast for 97L
Wind shear is expected to remain in the moderate 10-20 knot range the next three days, and waters will remain warm, 28-29°C. This should allow 97L to come close to tropical depression status 2-3 days from now. The GFDL, HWRF, and UKMET models develop 97L into a tropical storm by Monday. NHC is giving 97L a medium (20-50% chance) of developing into a tropical depression by Sunday. The storm is expected to track to the northwest over the open Atlantic, and shouldn't affect any land areas. By Wednesday, most of the models are predicting that an extratropical storm will form just north of Puerto Rico, and this storm will probably end up pulling 97L northwards into the Atlantic hurricane graveyard.

Elsewhere in the Atlantic
Most of the models continue to forecast the possible development of a tropical depression in the south central Caribbean, off the coast of Nicaragua, as early as Tuesday next week. A very moist atmosphere with low wind shear is predicted for the southern Caribbean next week, and I put the odds of a tropical storm forming there at 30%. The potential motion of such a storm is difficult to predict at this time.


Figure 2. Hurricane Norbert at 20:55 GMT October 8, 2008. At the time, Norbert was a Category 4 hurricane with 135 mph winds. Image credit: NASA Earth Observatory.

Hurricane Norbert weakens, then re-strengthens
Hurricane Norbert stalled out yesterday afternoon for several hours, which allowed the storm's churning winds to upwell large amounts of cold water, weakening the storm. Norbert has since resumed its track towards Mexico's Baja Peninsula, and is over warmer waters. Norbert also underwent an eyewall replacement cycle yesterday, which also served to weaken it. In an eyewall replacement cycle, the eyewall collapses, and gets replaced by a new eyewall that was concentric (at a greater diameter) with the old eyewall. These cycles typically take 1-2 days to complete, and the hurricane will remain relatively weak while it struggles to adjust to the new eyewall. The most recent microwave imagery suggests that this process is complete, as there is no trace of the old inner eyewall now. Infrared satellite loops show that the cloud tops of the eyewall clouds have cooled in recent hours, indicating that they are more vigorous and extend higher into the atmosphere. There is excellent upper-level outflow in all quadrants, and wind shear is moderate, near 10-15 knots. Satellite estimates of Norbert's strength indicate the storm has probably intensified into at least a Category 2 hurricane this morning. A Hurricane Hunter mission into Norbert is scheduled for this afternoon, and we will see if this intensification has actually taken place. Yesterday, the Hurricane Hunters found that a layer of stable air near the surface was preventing Norbert's strongest winds at high levels from mixing down to the surface. It still may be the case that Norbert has only Category 1 strength winds at the surface.

The computer models continue to be tightly clustered around a landfall in southwestern Baja near San Carlos, 150 miles north of the southern tip of Baja, on Saturday afternoon. The waters along Norbert's path are unusually warm for this time of year, about 1-3° C above average (Figure 3), and will increase in temperature to 29°C as Norbert approaches Baja. However, these warm waters do not extend very deep, and the total oceanic heat content is low. Once Norbert crosses Baja and enters the Gulf of California, total heat content increases, but Norbert will not be over these warm waters long enough to take advantage of them. Wind shear is expected to increase to a high 20-25 knots tonight. Given these factors, landfall Saturday afternoon as a Category 2 hurricane with 100-105 mph winds, as predicted by the GFDL and HWRF models, is a good forecast. The SHIPS models is weaker, putting Norbert at Category 1 strength with 85 mph winds. It is only 10-20% likely that Norbert would be a major Category 3 hurricane at landfall. Tropical storm force winds should extend outwards about 130 miles at landfall, so the southern tip of Baja (San Lucas) will probably see sustained winds of 30-35 mph, should Norbert hit near San Carlos, as predicted. One can look at the forecast radius of tropical storm force winds by clicking on the wundermap for Norbert, then selecting "wind radius" in the check boxes at the bottom of the page.

Crossing rugged Baja will probably knock Norbert down a full Category, by about 20-25 mph. The storm will still pack a solid punch when it makes it second landfall on mainland Mexico north of Los Mochis. Rainfall amounts in mainland Mexico will be 4-8 inches, and 6-10 inches over Baja. Norbert's remains should bring 1-2 inches of rain to portions of western Texas and southeastern New Mexico.


Figure 3. Departure of Sea Surface Temperature (SST) from average for October 6, 2008. Note the region being traversed by Norbert is 1-3 °C above average. Image credit: NOAA.

Odile dumping heavy rains on Mexico
Mexico has another storm to be concerned with, Tropical Storm Odile. Satellite estimates indicate Odile has dumped up to six inches of rain on the coast just east of Acapulco. Additional heavy rains of up to eight inches should affect the coast as Odile tracks along the coast, just offshore. Mexican radar and infrared satellite loops show that the heaviest rain is now offshore. However, heavy rain will likely move back onshore later today. Odile is under about 15 knots of wind shear, and this shear is forecast to remain in the 15-20 knot range the next 3-5 days. This should allow the storm to gradually intensify into a Categroy 1 hurricane.

Thursday update on Hurricane Ike relief efforts
Yesterday's update from Paul Timmons (Presslord) on the Hurricane Ike relief effort started by wunderground members Patrap, Presslord, and Stormjunkie:

While the devastating aftermath of hurricane Ike seems no longer to capture the interest of mainstream media, we all know that the needs continue. Chief Dickie Uzzle of the Bridge City, TX, fire department has informed us that only 14 homes in that community (population: 8700) did not sustain ruinous water damage. Many families continue to live in tents in front of their homes, with ALL of their personal belongings piled in the yard awaiting removal.

Laura Cremans, Manager of the Churches of Christ distribution center in Bridge City tells us " Only one truck of supplies has come here since Ike made landfall. We are desperate here."

This is the list of specific needs that we are currently attaining and working to attain for the rural populations and the disabilities community along the Texas Gulf Coast. We have worked closely with several local relief efforts as well as municipalities to identify these needs.

Undergarments
Socks
Men's & Women's Clothing (we already have a commitment for a substantial number of men's and women's pants)

Air Mattresses
Blankets/Sleeping bags
Tents
Insect repellent
All baby items
Formula (We have a commitment from Meade-Johnson to provide some of this)
Diapers
Rash cream
Wipes
Bottles

Our strategy is to focus on attaining as many of these items as possible through donations from manufacturers and distributors. In the last three and a half days, we have made several dozen contacts to this end and are beginning to get positive results; but we need your help.

If you have any contacts or influence which might facilitate us procuring the items listed above please contact us at presslord@aol.com or admin@stormjunkie.com. All your thoughts and ideas are good. The more input we have, the more impact we can have.This will help us successfully implement our strategy of expending donated funds primarily on transportation and logistics of moving donated goods. In this way, we can most effectively steward the donated funds in the most cost effective manner.

Moving forward...

Moving through October we are committed to adjusting our fund raising effort to leverage the grassroots enthusiasm and generosity generated by our Hurricane Ike relief work.  A more proactive approach will enhance our future effectiveness. We are asking you to consider committing to a monthly pledge amount.  The amount you pledge is less important then the consistency.  A dependable monthly donor base will allow us to strategically plan and prepare for the future and help us successfully execute those plans over the long term. 

Please give thoughtful, prayerful consideration to committing to a monthly pledge amount beginning November 1 and email your intentions to presslord@aol.com.

There is much work yet to be done in helping the victims of Ike. And there will certainly be other victims of other storms we can all serve. By continuing to work together as we have the last 3 1/2 weeks, we can have a profound positive impact on thousands of unserved, underserved, and forgotten people...

Also, please remember: we should all forward this information far and
wide...and frequently..

Thanks!!!!!

Contributions to this highly worthy portlight.org charity fund are fully tax-deductible, and will go to provide relief supplies for those smaller communities typically bypassed by the traditional relief efforts. More details can be found at StormJunkie's blog.

Jeff Masters

Updated: 2:26 PM GMT on October 10, 2008

Permalink

Powerful Norbert takes aim at Mexico's Baja

By: JeffMasters, 12:45 PM GMT on October 09, 2008

The tropical Atlantic is quiet, and no reliable computer models forecast tropical cyclone development over the next four days. The UKMET model continues to predict a tropical depression could spin up in the middle Atlantic between Africa and the Lesser Antilles Islands about five days from now. Climatology does not favor development in this region in October. A better chance for development will be over the Caribbean a week from now, and most of the models indicate the possibility of a Caribbean storm developing 5-7 days from now. The preferred genesis locations in the models are near the coast of Nicaragua, and near Puerto Rico.


Figure 1. Latest satellite image of Norbert.

Hurricane Norbert takes aim at Baja
Hurricane Norbert has weakened since yesterday's impressive Category 4 showing, but still remains a dangerous major hurricane over the Eastern Pacific Ocean. Infrared satellite loops show a well-formed eye with a large area of heavy thunderstorms, but the cloud tops have warmed today, indicating that they are not as vigorous and do not extend as high into the atmosphere. There is excellent upper-level outflow in all quadrants, and wind shear remains low, near 5 knots. The satellite appearance has not changed significantly in the past eight hours. Norbert may go through an eyewall replacement cycle today, where the main inner eyewall collapses, and a new outer eyewall forms. This process could cause a temporary weakening of the storm. The first Hurricane Hunter mission into Norbert is scheduled for this afternoon.

With the exception of the GFS, the computer models continue to be tightly clustered around a landfall in southwestern Baja near San Carlos, 150 miles north of the southern tip of Baja, on Saturday afternoon. The GFS solution of Norbert stalling off the coast and dissipating is unrealistic. Wind shear is about 5 knots over Norbert, and the waters are a warm 28.5°C. The waters along Norbert's path are unusually warm for this time of year, about 1-3° C above average (Figure 2). However, these warm waters do not extend very deep, and the total oceanic heat content is low. Once Norbert crosses Baja and enters the Gulf of California, total heat content increases, but Norbert will not be over these warm waters long enough to take advantage of the extra heat. As Norbert approaches Baja on Friday, wind shear is expected to increase to 15 knots and sea surface temperatures will cool to 27°C. These conditions will still support a major hurricane, and it is possible that Norbert will make landfall as a major hurricane. The latest 2 am EDT run of the GFDL model predicts landfall Saturday afternoon as a strong Category 2 hurricane with 110 mph winds. The latest HWRF model predicts a Category 3 hurricane with 120 mph winds. The SHIPS models is weaker, putting Norbert at Category 1 strength with 95 mph winds. The official NHC forecast of a Category 2 hurricane at landfall looks like a reasonable compromise. Tropical storm force winds should extend outwards about 130 miles at landfall, so the southern tip of Baja (San Lucas) will probably see sustained winds of 30-35 mph, should Norbert hit near San Carlos. One can look at the forecast radius of tropical storm force winds by clicking on the wundermap for Norbert, then selecting "wind radius" in the check boxes at the bottom of the page.

Crossing rugged Baja will probably knock Norbert down a full Category, by about 20-25 mph. The storm will still pack a solid punch when it makes it second landfall on mainland Mexico north of Los Mochis. Rainfall amounts in mainland Mexico will be 4-8 inches, and 6-10 inches over Baja. Norbert's remains should bring 1-2 inches of rain to portions of western Texas and southeastern New Mexico.


Figure 2. Departure of Sea Surface Temperature (SST) from average for October 6, 2008. Note the region being traversed by Norbert is 1-3 °C above average. Image credit: NOAA.

Baja hurricane history
Major hurricanes are rare on the Pacific Coast of Mexico, particularly as far north as Baja. Since record keeping began in 1949, only two Category 3 or stronger hurricanes have hit Baja (Figure 3). Hurricane Kiko of 1989 hit the east coast of Baja near Buenavista, as a Category 3 hurricane with 115 mph winds. Kiko produced destructive winds of up to 110 mph (180 km/h) in Cabo San Lucas, and caused severe damage throughout the southern tip of Baja California. Hurricane Oliva of 1967 made landfall as a Category 3 hurricane with 125 mph winds farther north on the east coast of Baja, in a sparsely populated area. No major hurricanes have hit the west coast of Baja since 1949, so Norbert would be the first on record if it maintains Category 3 strength at landfall.


Figure 3. Tracks of major hurricanes affecting Mexico's Baja Peninsula between 1949-2007. Image credit: NOAA Coastal Services Center.


Thursday update on Hurricane Ike relief efforts
Today's update from Paul Timmons (Presslord) on the Hurricane Ike relief effort started by wunderground members Patrap, Presslord, and Stormjunkie:

While the devastating aftermath of hurricane Ike seems no longer to capture the interest of mainstream media, we all know that the needs continue. Chief Dickie Uzzle of the Bridge City, TX, fire department has informed us that only 14 homes in that community (population: 8700) did not sustain ruinous water damage. Many families continue to live in tents in front of their homes, with ALL of their personal belongings piled in the yard awaiting removal.

Laura Cremans, Manager of the Churches of Christ distribution center in Bridge City tells us " Only one truck of supplies has come here since Ike made landfall. We are desperate here."

This is the list of specific needs that we are currently attaining and working to attain for the rural populations and the disabilities community along the Texas Gulf Coast. We have worked closely with several local relief efforts as well as municipalities to identify these needs.


Undergarments
Socks
Men's & Women's Clothing (we already have a commitment for a substantial number of men's and women's pants)

Air Mattresses
Blankets/Sleeping bags
Tents
Insect repellent
All baby items
Formula (We have a commitment from Meade-Johnson to provide some of this)
Diapers
Rash cream
Wipes
Bottles


Our strategy is to focus on attaining as many of these items as possible through donations from manufacturers and distributors. In the last three and a half days, we have made several dozen contacts to this end and are beginning to get positive results; but we need your help.

If you have any contacts or influence which might facilitate us procuring the items listed above please contact us at presslord@aol.com or admin@stormjunkie.com. All your thoughts and ideas are good. The more input we have, the more impact we can have.This will help us successfully implement our strategy of expending donated funds primarily on transportation and logistics of moving donated goods. In this way, we can most effectively steward the donated funds in the most cost effective manner.

Moving forward...

Moving through October we are committed to adjusting our fund raising effort to leverage the grassroots enthusiasm and generosity generated by our Hurricane Ike relief work.  A more proactive approach will enhance our future effectiveness. We are asking you to consider committing to a monthly pledge amount.  The amount you pledge is less important then the consistency.  A dependable monthly donor base will allow us to strategically plan and prepare for the future and help us successfully execute those plans over the long term. 

Please give thoughtful, prayerful consideration to committing to a monthly pledge amount beginning November 1 and email your intentions to presslord@aol.com.

There is much work yet to be done in helping the victims of Ike. And there will certainly be other victims of other storms we can all serve. By continuing to work together as we have the last 3 1/2 weeks, we can have a profound positive impact on thousands of unserved, underserved, and forgotten people...

Also, please remember: we should all forward this information far and
wide...and frequently..

Thanks!!!!!


Figure 3. Bridge City, Texas, after Hurricane Ike. Image credit: Stormjunkie.

Contributions to this highly worthy portlight.org charity fund are fully tax-deductible, and will go to provide relief supplies for those smaller communities typically bypassed by the traditional relief efforts. More details can be found at StormJunkie's blog.

Jeff Masters

Permalink

Norbert threatens Baja; midget Marco a record-breaker

By: JeffMasters, 2:10 PM GMT on October 08, 2008

The tropics are quiet in the Atlantic, and no reliable computer models forecast tropical cyclone development over the next four days. The UKMET model continues to predict a tropical depression could spin up in the middle Atlantic between Africa and the Lesser Antilles Islands about five days from now, but the GFS model has stopped predicting this. Climatology does not favor development in this region in October. A better chance for development will be over the Caribbean a week from now, and most of the models indicate the possibility of a Caribbean storm developing a 6-8 days from now.

Midget Marco sets a new record for the Atlantic
The hurricane season of 2008 has a new record--the kind of record we don't mind seeing! Tropical Storm Marco was the smallest tropical storm on record in the Atlantic. Records of tropical storm size only go back to 1988, so it is likely there have been other tropical storms as small as Marco in the past, though. If one looks at the maximum area covered by tropical storm force winds (in nautical miles squared, nm^2), given the radius of these winds for all four quadrants of each storm, the winners of the meekest of the meek award in the Atlantic are:

1) Marco, 2008, 1158 nm^2
2) Henri, 2001, 2238 nm^2
3) Bertha, 2002, 2827 nm^2
3) Bret, 2005, 2827 nm^2
3) Unnamed, 2006, 2827 nm^2

At Marco's peak size, tropical storm-force winds extended out 25, 15, 0, and 25 nm in its four quadrants. This means Marco covered an area of about 1,158 square nautical miles, which is slightly smaller than Rhode Island's area of 1,162 nm^2. Marco was about 1/75 as large as Ike at its peak, and 1/500 as big as the record holder, Tropical Storm Olga of 2001 (591000 nm^2, three times the size of Texas).

No casualties or damage were reported from Marco's landfall. The storm dumped up to six inches of rain along a 30-mile stretch of coast, according to satellite estimates.


Figure 1. Microwave image of Tropical Storm Marco superimposed on an infrared satellite image, shortly before landfall. Image credit: Navy Research Lab, Monterey.

Hurricane Norbert takes aim at Baja
Hurricane Norbert put on an impressive burst of rapid intensification last night, strengthening into the season's second major hurricane in the Eastern Pacific. Infrared satellite loops show a well-formed eye with a large area of heavy thunderstorms with cold cloud tops. There is excellent upper-level outflow in all quadrants. The satellite appearance has not changed significantly in the past six hours, and Norbert may have peaked in intensity. The first Hurricane Hunter mission into Norbert is scheduled for Thursday afternoon.

The NOGAPS, GFDL, HWRF, and UKMET models are tightly clustered around a landfall in southwestern Baja near San Carlos, 150 miles north of the southern tip of Baja, on Friday night or Saturday morning. However, the ECMWF and GFS predict Norbert will stall just offshore of Baja on Friday, and we cannot rule this possibility out yet. Wind shear is about 5 knots over Norbert, and the waters are a warm 28.5°C. As Norbert approaches Baja on Friday, wind shear is expected to increase to 15 knots and sea surface temperatures will cool to 27°C. These conditions can still support a major hurricane, and it is possible that Norbert will make landfall as a Category 3 hurricane. However, most of the intensity guidance predicts weakening of Norbert before landfall. The latest 2 am EDT run of the GFDL model predicts landfall Saturday morning as a Category 1 hurricane with 95 mph winds, as does the latest SHIPS model. The HWRF model, though, predicts a Category 3 hurricane with 125 mph winds at landfall. The official NHC forecast of a Category 2 hurricane at landfall looks like a reasonable compromise. Tropical storm force winds should extend outwards about 130 miles at landfall, so the southern tip of Baja (San Lucas) will probably see sustained winds of 35-40 mph, should Norbert hit near San Carlos. One can look at the forecast radius of tropical storm force winds by clicking on the wundermap for Norbert, then selecting "wind radius" in the check boxes at the bottom of the page.


Figure 2. Latest satellite image of Norbert.

Hurricane Ike relief efforts
Here's the latest update on the Hurricane Ike relief effort started by wunderground members Patrap, Presslord, and Stormjunkie:

The push to continue to keep supplies rolling to the Gulf Coast continues. This morning we shipped out three sets of packages with medical supplies and some cleaning supplies. The first set of two boxes went to the Bridge City Fire Department. It contained burn kits, bandages, first aid kits, Neosoprin, an air splint and more. The second set of boxes went to Eagle Heights Fellowship in Baytown. This is a shelter being run by a local pastor and seems to be one of the few shelters in this area that will remain open for the next four to six weeks. The supplies in these three boxes included CPR kits, first aid kits, disinfectant wipes, gloves, and more. The third set of three boxes were shipped to EmmyRose which she will personally deliver to the San Leon/Baycliff area. They included many of the same items listed above. We have estimated the value of these seven boxes to be between $4000 and $5000 which we shipped for just under $350.

Contributions to this highly worthy portlight.org charity fund are fully tax-deductible, and will go to provide relief supplies for those smaller communities typically bypassed by the traditional relief efforts. More details can be found at StormJunkie's blog.

Jeff Masters

Permalink

Midget Marco makes landfall

By: JeffMasters, 1:36 PM GMT on October 07, 2008

Tropical Storm Marco is making landfall along the Mexican Gulf of Mexico coast northwest of Veracruz. We really don't know how strong this storm is, because these so-called "midget" tropical cyclones are very difficult to classify correctly via satellite estimates. The only way to get an accurate idea of the strength of Marco is to fly a Hurricane Hunter airplane into the storm, and there has been only one flight into Marco (yesterday afternoon's flight). No further missions are planned.


Figure 1. Comparison of the sizes of Hurricane Ike and Tropical Storm Marco. Ike image was taken on September 11, 2008 (image credit: NASA. The Marco image was taken at 5 pm EDT October 6.

Midget tropical cyclones are rare in the Atlantic, but are fairly common the Western Pacific, where the presence of the monsoon trough often acts to spin up tiny tropical cyclones. Although small in stature, midget tropical cyclones are capable of intensifying into powerful hurricanes capable of causing severe damage. Tropical Cyclone Tracy, which hit Darwin, Australia on Christmas Day in 1974, was a midget tropical cyclone as small as Marco, but packed Category 4 winds. The storm killed 71 people and caused over $5 billion in damage.

Data yesterday afternoon from the Hurricane Hunters suggested that Marco's eye was just 3 miles across. Tropical storm force winds extended outward only ten miles from the center. Tropical storms this small are subject to sudden and unpredictable changes in intensity, and it wouldn't surprise me to see Marco with winds anywhere between 40 mph and 80 mph at landfall. The region affected will be just 10-20 miles across, and we don't need to worry about any significant storm surge with this storm! According to the latest analysis by NOAA's Hurricane Research Division, the Integrated Kinetic Energy (IKE) for Marco is as low as you'll see for a tropical storm: zero. They rate Marco's potential surge damage as a 0.3 on a scale of 1 to 6. For comparison, Ike and Katrina rated a 5.1 shortly before they made landfall. Comparing Marco to Ike (Figure 1), we can see that Ike was a Texas-sized storm that filled the entire Gulf of Mexico. Ike's tropical storm-force winds extended out up to 275 miles from the center at landfall. Marco is a Rhode Island-sized storm. At Marco's peak size, tropical storm-force winds covered an area of about 1,158 nm, which is 1/75 as big as Ike's.


Figure 2. Current satellite image Marco.

Elsewhere in the tropics
A small circulation near 11N, 37W, midway between Africa and the Lesser Antilles Islands, is kicking up some isolated heavy thunderstorms. The region is under about 20-30 knots of wind shear. The GFS and UKMET models continue to predict that a tropical depression could spin up in this region by Friday, and wind shear is predicted to drop to a level that might allow that to happen.

We will also need to watch the Western Caribbean for possible development late this week.

Hurricane Ike relief efforts
Here's today's update on the Hurricane Ike relief effort started by wunderground members Patrap, Presslord, and Stormjunkie:

The push to continue to keep supplies rolling to the Gulf Coast continues. This morning we shipped out three sets of packages with medical supplies and some cleaning supplies. The first set of two boxes went to the Bridge City Fire Department. It contained burn kits, bandages, first aid kits, Neosoprin, an air splint and more. The second set of boxes went to Eagle Heights Fellowship in Baytown. This is a shelter being run by a local pastor and seems to be one of the few shelters in this area that will remain open for the next four to six weeks. The supplies in these three boxes included CPR kits, first aid kits, disinfectant wipes, gloves, and more. The third set of three boxes were shipped to EmmyRose which she will personally deliver to the San Leon/Baycliff area. They included many of the same items listed above. We have estimated the value of these seven boxes to be between $4000 and $5000 which we shipped for just under $350.


Figure 3. More relief supplies on the way!

Contributions to this highly worthy portlight.org charity fund are fully tax-deductible, and will go to provide relief supplies for those smaller communities typically bypassed by the traditional relief efforts. More details can be found at StormJunkie's blog.

Jeff Masters

Updated: 8:55 PM GMT on October 07, 2008

Permalink

Marco is born

By: JeffMasters, 9:42 PM GMT on October 06, 2008

Surprising Tropical Storm Marco has burst onto the scene in the extreme southern portion of the Gulf of Mexico. In just five hours, the tiny storm has spun up to near hurricane strength, a remarkable rapid intensification feat. Visible satellite loops show a tiny storm with a concentrated area of heavy thunderstorms, moving west-northwest at about 10 mph. In another example of why we need the Hurricane Hunters, an Air Force airplane that scrambled to fly Marco with little advance notice found top winds of 65 mph and a 998 mb pressure at 4:19 pm EDT. Satellite estimates using the traditional Dvorak Technique were still classifying Marco as a tropical depression with 35 mph winds this afternoon. It currently appears that Marco is not strengthening, as the latest pass by the Hurricane Hunters through the eye at 5:19 pm EDT found no change in pressure, and peak surface winds of about 60 mph.


Figure 1. Current satellite image Marco.

Marco won't be over water long, but its recent shift to a more northwesterly track may keep the storm over water long enough to allow it to become a Category 1 hurricane.

Hurricane Ike relief efforts
The need is still great for relief in the regions hard-hit by Hurricane Ike. Please consider donating to the relief effort started by wunderground members Patrap, Presslord, and Stormjunkie. Contributions to this portlight.org charity fund are fully tax-deductible, and will go to provide relief supplies for those smaller communities typically bypassed by the traditional relief efforts. More details can be found at StormJunkie's blog.

Jeff Masters

Updated: 10:05 PM GMT on October 06, 2008

Permalink

Mexican Bay of Campeche disturbance may become a tropical depression

By: JeffMasters, 2:12 PM GMT on October 06, 2008

A small but well-defined disturbance (96L) has moved off of Mexico's Yucatan Peninsula, into the southernmost Gulf of Mexico (the Bay of Campeche). The low is moving west-northwest at 10-15 mph. Visible satellite loops show a small but concentrated area of heavy thunderstorms associated with the low. A surface circulation is not evident in satellite loops, or in this morning's QuikSCAT pass. Wind shear is low, in the 5-10 knot range.


Figure 1. Current satellite image of the Bay of Campeche disturbance, 96L. Image credit: NOAA.

The system won't be over water long, but is sufficiently well-organized that is may be able to organize into a tropical depression or tropical storm. Landfall should occur on the Mexican coast in the southwestern Bay of Campeche, near Veracruz, tonight or Tuesday morning. However, the latest 06Z (2 am EDT) run of the HWRF model takes 96L northwestward, keeping it over water until Tuesday afternoon. This model run intensifies 96L into a 60 mph tropical storm before making landfall near Poza Rica late Tuesday afternoon. The topography of the southernmost Bay of Campeche often acts to spin up tropical systems, and I give this storm a 60% chance of becoming a tropical depression, and a 30% chance of becoming a tropical storm. NHC is currently giving 96L a medium (20-50% chance) of developing into a tropical depression. Heavy rains of 3-6 inches can be expected in a small area near where 96L comes ashore.

Elsewhere in the tropics
A small closed circulation has developed in the middle Atlantic Ocean, near 13N 30W, about 400 miles west-southwest of the Cape Verdes Islands, as seen on this morning's QuikSCAT pass. This disturbance is under about 30 knots of wind shear, which is too high for development to occur. Wind shear is expected to stay near 25-30 knots over the disturbance the next three days, which should keep it from developing. NHC is giving this disturbance a low (<20% chance) of developing.

There may be a better chance for development for a tropical wave that moved off the coast of Africa today. The GFS and UKMET models predict that this wave will spin up into a tropical depression by Thursday this week.

Hurricane Ike relief efforts
The need is still great for relief in the regions hard-hit by Hurricane Ike. Please consider donating to the relief effort started by wunderground members Patrap, Presslord, and Stormjunkie. Contributions to this portlight.org charity fund are fully tax-deductible, and will go to provide relief supplies for those smaller communities typically bypassed by the traditional relief efforts. More details can be found at StormJunkie's blog.

Jeff Masters

Updated: 2:15 PM GMT on October 06, 2008

Permalink

A quiet Sunday in the tropics

By: JeffMasters, 3:35 PM GMT on October 05, 2008

A broad area of low pressure is over Mexico's Yucatan Peninsula, moving westward at 10-15 mph. Visible satellite loops show scattered heavy thunderstorms associated with the low. A surface circulation is also evident near the Guatemala/Mexico border. Wind shear is moderate, in the 10-15 knot range.


Figure 1. Current satellite image of the Western Caribbean. Image credit: NOAA.

The disturbance moving westward, and will emerge over the Gulf of Mexico in the Bay of Campeche on Monday. The system may be able to organize into a tropical depression once it emerges into the Gulf. However, the system will not have much time over water before it makes landfall again on the Mexican coast in the southwestern Bay of Campeche. NHC is currently giving the system a low (<20% chance) of developing into a tropical depression by Tuesday.

Elsewhere in the tropics
The InterTropical Convergence Zone (ITCZ), a semi-permanent band of heavy thunderstorms off the coast of Africa, is unusually active for this time of year. The GFS model continues to predict that a tropical depression will spin up out of the ITCZ late this week. None of the other reliable models go along with this, however, and it is unusual to get a storm developing in this region this late in the season.


Hurricane Ike relief efforts
The need is still great for relief in the regions hard-hit by Hurricane Ike. Please consider donating to the relief effort started by wunderground members Patrap, Presslord, and Stormjunkie. Contributions to this portlight.org charity fund are fully tax-deductible, and will go to provide relief supplies for those smaller communities typically bypassed by the traditional relief efforts. More details can be found at StormJunkie's blog.

Jeff Masters

Permalink

Western Caribbean disturbance moving over the Yucatan

By: JeffMasters, 2:01 PM GMT on October 04, 2008

Heavy thunderstorm activity in association with a broad area of low pressure over the Western Caribbean remains disorganized today. Visible satellite loops show a modest area of heavy thunderstorms, with no sign of organization or a surface circulation. This morning's QuikSCAT pass showed no signs of a surface circulation, either. Wind shear is moderate, in the 10-15 knot range.


Figure 1. Current satellite image of the Western Caribbean. Image credit: NOAA.

The disturbance is drifting westward, and should move over northern Guatemala, Belize, and Mexico's Yucatan Peninsula today before it can develop into a tropical depression. These areas can expect heavy rains of 2-4 inches today through Sunday from the disturbance. NHC is currently giving it a low (<20% chance) of developing into a tropical depression.

Elsewhere in the tropics, the NOGAPS model is forecasting the possible formation of a tropical depression off the coast of Nicaragua on Thursday, while the GFS model thinks something might develop off the coast of Africa Thursday. It's a little late to be getting an African storms developing, so I doubt the GFS forecast. However, we'll need to watch the Western Caribbean over the coming week.

Links to follow
Wundermap for the Western Caribbean


Hurricane Ike relief efforts
When a major hurricane hits, relief efforts are always confused and don't reach many areas with great needs. Thus, a group of wunderground bloggers mobilized the day after Ike hit to help out. Their goal was to provide immediate help where traditional aid efforts were coming short, with a focus on providing equipment for people with disabilities and a full spectrum of relief supplies to smaller communities often neglected. Traditional, professional relief efforts are weighed down by bureaucracy and cannot respond as nimbly as smaller, grass-roots relief efforts can. I believe our dollars have been well-spent by the relief effort organized by our own Patrap, Presslord, and Stormjunkie, under the banner of Portlight Strategies, Inc. I encourage you to donate to the cause, or the traditional charity organization of your choice.

Here's a breakdown of how much money has been donated, and how much spent. Figures are rounded to the nearest $100. More details can be found on StormJunkie's blog:

Total money donated: $31,200 (about 400 donors)
Total money spent so far: $10,350
Total money in the portlight.org checking account: $21,000
--$9,000 in escrow for legal defense
--$12,000 available for immediate relief operations
Total money in the original Paypal account set up by Patrap: $1000
Total money in the new Paypal account set up by Presslord: $250

Here's how the $10350 has been spent:

WalMart - $2000 - supplies
Costco - $1000 - supplies
Patrick Pearson (Patrap) - $1000 (fuel, rental costs for a truck)
Truck from Charleston - $1500 - fuel
Florida supply truck - $2100 - escort, credentialing, fuel, vehicle repair, lodging
Crew food,lodging, transport home - $1000
Truck rental, gas for truck from Atlanta - $1750

The biggest coup for the effort came when portlight arranged to get about $150,000 worth of medical equipment donated to the cause. Rob Ingham (AKA Rainman32) and Roger Knight (AKA NLimbo) took a rented truck to Atlanta, grabbed the gear, and delivered it to Houston. In the shipment:

Four Gaylord boxes medical supplies
-Soft casts
-various catheter kits
-catheter bags
-oxygen tubing kits
-other misc. medical supplies
13 hospital bed mattresses and pressure pads
2 Gaylord boxes of sanitized walkers (20 per box)
4 Gaylord boxes of unsanitized walkers (20 per box)
2 pallets with two electric wheelchairs each (4)
100 pairs of crutches
30 bedside commodes sanitized
6 gerry chairs

Jeff Masters

Permalink

Western Caribbean disturbance flares up

By: JeffMasters, 3:37 PM GMT on October 03, 2008

Heavy thunderstorm activity has increased substantially this morning in association with a broad area of low pressure over the Western Caribbean. Visible satellite loops show a modest but expanding area of heavy thunderstorms, with no sign of organization or a surface circulation. Wind shear is moderate, in the 10-20 knot range. The disturbance is moving very little at present.


Figure 1. Current satellite image of the Western Caribbean. Image credit: NOAA.

Steering currents are weak in the Western Caribbean, and there should be little motion of the system over the next three days. Heavy rain from the disturbance has already moved into the Cayman Islands, and will begin to affect northern Honduras, western Cuba, and Mexico's Yucatan Peninsula over the next two days. None of the computer models develop this disturbance. However, with wind shear expected to stay in the moderate 10-15 knot range through Sunday, and the upper level winds expected to take on an anticyclonic flow, I give this disturbance a medium (20-50% chance) of developing into a tropical depression by Sunday. NHC is currently giving it a low (<20% chance) of developing.

Links to follow
Wundermap for the Western Caribbean
Grand Cayman weather


Jeff Masters

Updated: 3:38 PM GMT on October 03, 2008

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October hurricane season outlook

By: JeffMasters, 1:51 PM GMT on October 02, 2008

Climatologically, the first half of October is part of the peak portion of hurricane season. Activity does not begin to drop off significantly until mid-October (Figure 1). During the 13-year active Atlantic hurricane period that began in 1995, we've averaged 2.7 named storms, 1.1 hurricanes, and 0.5 intense hurricanes during the month of October. The busiest October on record was 2005, when seven named storms, three hurricanes, and one intense hurricane occurred (including Wilma, the strongest hurricane on record).


Figure 1. Climatology of Atlantic hurricanes and tropical storms.

Far fewer Cape Verdes-type hurricanes form between Africa and the Lesser Antilles Islands during October, compared to September (Figure 2). Many of those that do form recurve out to sea, and the odds are that hurricane season is over for the Lesser Antilles Islands. Only four October hurricanes have affected these islands since 1851. Hurricane season is also probably over for Texas, which which has only seen three October hurricanes since 1851. Hurricane season is definitely not over for Central America, Mexico's Yucatan Peninsula, the U.S. coast from Louisiana to New England, plus Bermuda, the Bahamas, and the islands of the central and western Caribbean.


Figure 2. Tracks of all hurricane and tropical storms forming in the first half of October.

Sea Surface Temperatures
Sea Surface Temperatures (SSTs) and oceanic heat content are declining now, but are still plenty warm enough to support a major hurricane in some regions. In particular, the entire Caribbean is 0.5-1.0°C above average in temperature, as are the waters off the U.S. East Coast (Figure 3). The waters of the Gulf of Mexico and Bahamas are quite cool, due to the lingering effects of the passage of Hurricanes Ike and Gustav. Due to these SST patterns, a major hurricane would be most likely to affect the Western Caribbean.


Figure 3. Departure of Sea Surface Temperature (SST) from average for October 2, 2008. Image credit: NOAA.

Wind Shear
The latest 15-day wind shear forecast from the GFS model predicts that wind shear across the tropical Atlantic will remain in the average to below average range. In the longer term, wind shear is predicted by NOAA's CFS model to remain below average over the Caribbean for October through December.

When will activity pick up again?
There is an oscillation in the atmosphere I've talked a little about, called the Madden-Julian Oscillation (MJO). The MJO is a pattern of enhanced rainfall that travels along the Equator, and can act to boost hurricane activity when it propagates into the Atlantic. The MJO has a period of about 30-60 days, and is currently in its active phase over the Atlantic. According to the latest 15-day GFS model forecast and the MJO discussion from the National Weather Service's Climate Prediction Center, we are expected to remain in an active phase for the MJO over the Atlantic for at least the next two weeks. This year, the active phase of the MJO has been strongly correlated with formation of named storms in the Atlantic. According to the latest analysis by Phil Klotzbach of Colorado State University (Table 4, below), ten of the last eleven named storms in the Atlantic this year formed during an active phase of the MJO. We can anticipate an above average chance of tropical storm formation in the Atlantic this October as a result.



The forecast
Due to above average SSTs in the Caribbean, an active phase of the MJO, and average to below average wind shear over the tropical Atlantic this month, we can expect levels of tropical storm activity similar to what has been seen in past Octobers, since the current active hurricane phase began in 1995. However, the models are showing nothing forming over the next week, and the tropics look pretty quiet right now. In consequence, I am expecting two named storms and one hurricane this month. There is a 50/50 chance this hurricane will be an intense hurricane. The October forecast from Colorado State University is more aggressive, and calls for 3 named storms, 2 hurricanes, and one major hurricane.

Steering currents
Now that it is October, the jet stream is more active and farther south, resulting in increased chances of recurvature for tropical cyclones. However, the latest 15-day GFS model forecast predicts more high pressure than usual over the Eastern U.S., which will result in longer recurvature delays than is usual for October storms. Thus, the risk of an October hurricane hitting the U.S. East Coast is higher than average this year.

Summary of Hurricane Ike relief efforts
When a major hurricane hits, relief efforts are always confused and don't reach many areas with great needs. Thus, a group of wunderground bloggers mobilized the day after Ike hit to help out. Their goal was to provide immediate help where traditional aid efforts were coming short, with a focus on providing equipment for people with disabilities and a full spectrum of relief supplies to smaller communities often neglected. Traditional, professional relief efforts are weighed down by bureaucracy and cannot respond as nimbly as smaller, grass-roots relief efforts can. I believe our dollars have been well-spent by the relief effort organized by our own Patrap, Presslord, and Stormjunkie, under the banner of Portlight Strategies, Inc. They have responded quickly and delivered much-needed aid to communities hard-hit by Ike that were being under-served. The people involved in the relief effort were very passionate about serving, and they have sacrificed their time, sleep, health, and money to support this cause. I support their efforts to continue spending the money that was donated to the cause in the way intended. The passion they put into this effort led to conflicts when disagreements arose over how to operate this effort, though. In the haste to go from zero to 100 mph in a few days, and without a supporting bureaucracy or strategic plan to guide their efforts, it should be no surprise that there was confusion and mis-communication. I do not fault any of the people involved for the problems that have arisen. Rather, blame Hurricane Ike! Hurricanes cause chaos, and there was certainly plenty of that on the blogs last weekend. It's good to have these kinds of problems, which are, in part, due to the extraordinary and unexpected generosity of all of you who have contributed.

During a one hour conference call I participated in yesterday, Paul Timmons, Jr. (AKA Presslord), one of the founding Board members of portlight.org, pulled together a new advisory board for portlight.org. The board members are myself, Patrick Pearson (Patrap), John Wilbanks (Storm Junkie), Rob Ingham (Rainman32), Deb Nowinski (EmmyRose), and Kelly Timmons (Paul's wife, and accountant for Portlight.org). It was agreed at the meeting that Paul would been given the final authority to write all checks, but that the board would advise him on how the money should be spent. When a check is written, all members of the board will receive a notification via email. The current plan is to spend the available funds to deliver donated goods (mostly medical equipment for people with disabilities) to the Hurricane Ike devastation areas. The goods will be delivered by ground freight shipments, and by rented trucks driven by some of the advisory board members. About $9000 of the donated money will not be spent at this time, because it has been put in escrow at the advice of Portlight's lawyer. This money is being held in escrow because of the threat of legal action made against Portlight in the chaos last weekend. The money will remain in escrow until Portlight's lawyer advises them otherwise.

Now that the chaos has subsided and everyone on the advisory board has agreed we should move ahead, I am ready to once again endorse contributions. The WUBA Hurricane Ike relief fund, initially founded by Patrap, is controlled by Portlight Strategies, Inc., a 501c3 charity run by Paul Timmons, Jr. (Presslord) and three other board members. All donations are 100% tax deductible. The mission statement of Portlight is co-opting with individuals as well as other organizations to cut through red tape in order to directly meet the specific needs of unserved, under served, and forgotten people.

Donations can be sent via check and via PayPal. The funds are then transferred to the portlight.org checking account, and Presslord has been writing checks from this account to fund the relief efforts. As of this writing, there is about $1000 "stuck" in a defunct PayPal account because of a dispute over protocol. An agreement has been reached that this money will be released to the portlight.org checking account and used to fund relief efforts, though. Here's a breakdown of how much money has been donated, and how much spent. Figures are rounded to the nearest $100. More details can be found on StormJunkie's blog:

Total money donated: $31,200 (about 400 donors)
Total money spent so far: $10,350
Total money in the portlight.org checking account: $21,000
--$9,000 in escrow for legal defense
--$12,000 available for immediate relief operations
Total money in the original Paypal account set up by Patrap: $1000
Total money in the new Paypal account set up by Presslord: $250

Here's how the $10350 has been spent:

WalMart - $2000 - supplies
Costco - $1000 - supplies
Patrick Pearson (Patrap) - $1000 (fuel, rental costs for a truck)
Truck from Charleston - $1500 - fuel
Florida supply truck - $2100 - escort, credentialing, fuel, vehicle repair, lodging
Crew food,lodging, transport home - $1000
Truck rental, gas for truck from Atlanta - $1750

The biggest coup for the effort came when Paul arranged to get about $150,000 worth of medical equipment donated to the cause. Rob Ingham (AKA Rainman32) and Roger Knight (AKA NLimbo) received took a rented truck to Atlanta, grabbed the gear, and delivered it to Houston. In the shipment:

Four Gaylord boxes medical supplies
-Soft casts
-various catheter kits
-catheter bags
-oxygen tubing kits
-other misc. medical supplies
13 hospital bed mattresses and pressure pads
2 Gaylord boxes of sanitized walkers (20 per box)
4 Gaylord boxes of unsanitized walkers (20 per box)
2 pallets with two electric wheelchairs each (4)
100 pairs of crutches
30 bedside commodes sanitized
6 gerry chairs

I've been impressed by the dedication and effort put into this work by all the people involved. This is a much-needed humanitarian effort that has sprung up from the remarkable community we have here. I thank each one of you for participating. I do ask that all comments about the relief efforts on this blog be positive ones. There is no need to point out the mistakes of the past, which are painfully obvious. Portlight has plans to extend this effort into the future, and I plan to become a regular donor in coming years for the future hurricane disasters that will inevitably visit our shores.

If there's no activity or forecast activity in the tropics, I may leave this blog up for a few days.

Jeff Masters

Updated: 5:06 PM GMT on October 02, 2008

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Laura dying; tropics look quiet

By: JeffMasters, 12:45 PM GMT on October 01, 2008

Well, it's October, and we're into the final month of peak hurricane season. Things look pretty quiet right now, and I don't see anything on the horizon meriting concern. Subtropical Storm Laura is almost dead, done in by cold North Atlantic waters. Visible satellite images show very little heavy thunderstorm activity, and Laura is currently transitioning into an extratropical storm. The remains of Laura will probably bring 45 mph winds to the coast of the British Isles on Sunday.


Figure 1. Latest satellite image of Laura.

Elsewhere in the tropics
A trough of low pressure extends from the Western Caribbean northeastwards over Cuba and the Bahamas. Thunderstorm activity is relatively weak and scattered along this trough. None of the models predict development in the Western Caribbean along this trough over the coming week. Development off the east coast of Florida, near the northwestern Bahamas, is possible late this week, but any such storm would move northeastward out to sea.

Hurricane Ike portlight.org charity relief efforts
I've agreed to act as an advisor for the Hurricane Ike portlight.org charity relief efforts spearheaded by Patrap, Presslord, and StormJunkie. I'll be participating in a conference call with them this afternoon, and will write up a summary of the effort that I plan to post tomorrow.

I'll post an Atlantic hurricane outlook for the month of October in Thursday's post.

Jeff Masters

Updated: 4:17 PM GMT on October 01, 2008

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About

Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.