CSU predicts highly active hurricane season; Cyclone Phet approaching Oman
A very active Atlantic hurricane season is on tap for 2010, according to the seasonal hurricane forecast issued June 2 by Dr. Phil Klotzbach and Dr. Bill Gray of Colorado State University (CSU). The CSU team is calling for 18 named storms, 10 hurricanes, and 5 intense hurricanes, and an Accumulated Cyclone Energy (ACE) 185% of average. Between 1950 - 2000, the average season had 10 named storms, 6 hurricanes, and 2 intense hurricanes. But since 1995, the beginning of an active hurricane period in the Atlantic, we've averaged 14 named storms, 8 hurricanes, and 4 intense hurricanes per year. The new forecast is a step up from their April forecast, which called for 15 named storms, 8 hurricanes, and 4 intense hurricanes. The new forecast calls for a much above-average chance of a major hurricane hitting the U.S., both along the East Coast (51% chance, 31% chance is average) and the Gulf Coast (50% chance, 30% chance is average). The risk of a major hurricane in the Caribbean is also high, at 65% (42% is average.) This is the most aggressive early June forecast ever issued by the CSU group; the previous most aggressive such forecasts were for the 2006 and 2007 seasons, when the CSU team predicted 17 named storms, 9 hurricanes, and 5 intense hurricanes. Both of these forecasts did poorly, particularly the 2006 forecast, as only 10 named storms, 5 hurricanes, and 2 intense hurricanes were observed.
The forecasters cited four main reasons for an active season:
1) Weak La Niña conditions should develop by the most active portion of this year's hurricane season (August-October). The expected trend towards weak La Niña conditions should lead to reduced levels of vertical wind shear compared with what was witnessed in 2009.
2) Current SST anomalies are running at near-record warm levels. These very warm waters are associated with dynamic and thermodynamic factors that are very conducive for an active Atlantic hurricane season.
3) A weaker-than-normal Azores High prevailed during April-May. Weaker high pressure typically results in weaker trade winds that are commonly associated with more active hurricane seasons.
4) We are in the midst of a multi-decadal era of major hurricane activity, which began in 1995. Major hurricanes cause 80-85 percent of normalized hurricane damage.
Analogue years
The CSU team picked four previous years when atmospheric and oceanic conditions were similar to what we are seeing this year: weak El Niño to neutral conditions, well above-average tropical Atlantic SSTs, and above-average far North Atlantic SSTs during April - May. Those four years were 2005, the worst hurricane season of all time; 1969, the 3rd worst hurricane season of all time, featuring Category 5 Hurricane Camille which hit Mississippi; 1966, a relatively average year that featured Category 4 Inez that killed 1,000 people in Haiti; and 1958, a severe season with 5 major hurricanes. The mean activity for these five years was 17 named storms, 10 hurricanes, and 5 intense hurricanes, almost the same as the 2009 CSU forecast.
How accurate are the June forecasts?
The June forecasts by the CSU team over the past 12 years have had a skill 19% - 30% higher than a "no-skill" climatology forecast for number of named storms, number of hurricanes, and the ACE index (Figure 1). This is a decent amount of skill for a seasonal forecast, and these June forecasts can be useful to businesses such as the insurance industry and oil and gas industry that need to make bets on how active the coming hurricane season will be. Unfortunately, the CSU June 1 forecasts do poorly at forecasting the number of major hurricanes (only 3% skill), and major hurricanes are what do 80 - 85% of all hurricane damage (normalized to current population and wealth levels.) This year's June forecast uses the same formula as the past two years, which did quite well predicting the 2008 hurricane season (prediction: 15 named storms, 8 hurricanes, 4 intense hurricanes; observed: 16 named storms, 8 hurricanes, 5 intense hurricanes) and 2009 hurricane season (prediction: 11 named storms, 5 hurricanes, 2 intense hurricanes; observed: 9 named storms, 3 hurricanes, 2 intense hurricanes.) An Excel spreadsheet of their forecast skill (expressed as a mathematical correlation coefficient) show values from 0.44 to 0.58 for their June forecasts, which is respectable.
Figure 1. Comparison of the percent improvement over climatology for May and August seasonal hurricane forecasts for the Atlantic from NOAA, CSU and TSR from 1999-2009 (May) and 1998-2009 (August), using the Mean Squared Error. The British firm Tropical Storm Risk (TSR) will issue their outlook for the 2010 Atlantic hurricane season on June 4. Image credit: Verification of 12 years of NOAA seasonal hurricane forecasts, National Hurricane Center.
NOAA's 2010 hurricane season forecast
NOAA issued their forecast for the upcoming Atlantic hurricane season last week. As I discussed in my post on their forecast, NOAA is calling for very active and possibly hyperactive season. They give an 85% chance of an above-normal season, a 10% chance of a near-normal season, and just a 5% chance of a below-normal season. NOAA predicts a 70% chance that there will be 14 - 23 named storms, 8 - 14 hurricanes, and 3 - 7 major hurricanes, with an Accumulated Cyclone Energy (ACE) in the 155% - 270% of normal range. If we take the midpoint of these numbers, NOAA is calling for 18.5 named storms, 11 hurricanes, 5 major hurricanes, and an ACE index 210% of normal. A season with an ACE index over 175% is considered "hyperactive."
Figure 2. Visible satellite image of Tropical Cyclone Phet on Thursday, June 3, 2010.
Tropical Cyclone Phet the 2nd strongest Arabian Sea storm on record
Record heat over southern Asia in May has helped heat up the Arabian Sea to 2°C above normal, and the exceptionally warm SSTs helped fuel Tropical Cyclone Phet into the second strongest tropical cyclone ever recorded in the Arabian Sea. Phet peaked at Category 4 strength with 145 mph winds yesterday, and has weakened slightly to 135 mph winds this morning. Only Category 5 Cyclone Gonu of 2007, which devastated Oman, was a stronger Arabian Sea cyclone.
Phet is over very warm waters of 30 - 31°C, and is under moderate wind shear of 10 - 20 knots. However, the storm is wrapping in dry air from the Arabian Peninsula, which has caused weakening. Visible satellite imagery from this morning (Figure 2) shows that the heavy thunderstorms on the north side of Phet have been eroded away by dry air. Phet is a small storm, and could fall apart fairly quickly if dry air can penetrate into its core. This should happen later today, since wind shear is on the increase, and the shearing winds should be able to disrupt the circulation enough that dry air can force its way into Phet's eyewall. Phet is fairly small, will miss the most heavily populated areas of Oman, and will likely undergo significant weakening before landfall, so the storm is unlikely to cause the kind of catastrophic flooding that Category 5 Cyclone Gonu of 2007 brought to Oman. Gonu killed 50 people and did $4.2 billion in damage. Phet's heaviest rains will be confined to a relatively sparsely populated region of Oman's coast. Rainfall amounts in excess of 6 inches in 18 hours (Figure 3) can be expected along Oman's coast today, which will likely cause extreme flooding.
After Phet's encounter with Oman, the storm will probably be at tropical storm strength when it makes its second landfall in Pakistan. Heavy rains from Phet will be the major danger for Pakistan, and serious flooding can be expected over southern Pakistan.
Figure 3. Forecast rain amounts for the 18-hour period ending at 2am EDT June 3, 2010. Image credit: NOAA/NESDIS.
Oil spill update
Onshore winds out of the south, southwest, or west are expected to blow over the northern Gulf of Mexico over most of the next week, resulting increased threats of oil to Alabama, Mississippi, and the Florida Panhandle, according to the latest trajectory forecasts from the State of Louisiana. The latest ocean current forecasts from the NOAA HYCOM model show that these winds will generate a 0.5 - 1 mph current flowing from west to east along the Florida Panhandle coast Sunday and Monday. If this current develops as predicted, it will be capable of bringing light amounts of oil as far east as Fort Walton Beach, Florida, by Monday. If you spot oil, send in your report to http://www.gulfcoastspill.com/, whose mission is to help the Gulf Coast recovery by creating a daily record of the oil spill.
Oil spill resources
My post, What a hurricane would do the Deepwater Horizon oil spill
My post Wednesday with answers to some of the common questions I get about the spill
My post on the Southwest Florida "Forbidden Zone" where surface oil will rarely go
My post on what oil might do to a hurricane
Gulf Oil Blog from the UGA Department of Marine Sciences
Oil Spill Academic Task Force
University of South Florida Ocean Circulation Group oil spill forecasts
ROFFS Deepwater Horizon page
Synthetic Aperture Radar (SAR) imagery from the University of Miami
I'll be back Friday with an analysis of the new TSR hurricane forecast and a new forecast by a promising Florida State University model.
Jeff Masters
Reader Comments
Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 — Blog Index
goes across the north gulf coast states it will bring
even more oil inland to the shore line.....
From LA to FL
I think more people would show up, but everybody is afraid to put their own health at risk. I heard on the news that 1 in 7 people that help with the cleanup are expected to get cancer from it. Where they get these stats I don't know, but I don't like those odds.
You know thats one one of the tropical waves over Africa....while I do not put much faith in long-range models this illustrates why even those AEWs over African need to be watched.
Temporary, until they finish the relief well somewhere between the end of July and December, and if that works.
.."Sometimes the needs of the many, outweigh the needs of a few..
Or the one"...
Yup...potential trouble-makers once they get to the west. The thing about that particular run was the pattern across the MDR. If you look at the 1012mb isobar compared to the recent runs, it was way up to the north on the 6z run. Those waves had a very northerly path into the Caribbean.
06z
18z (recent)
Link
Lol. Thanks a lot!! :)
Yea...its actually our wave that emerged a few days ago.
Which is exactly why the current tropical wave in the Central Atlantic can't be ruled out. It might be dying, but in the GOM those things can literally reform convection out of nowhere. Like Claudette of last year, or Tropical Storm Charley of '98.
He's more then a marine biologist...also a so called expert on the situation. He was on Olbermann's show. Re-airs at 9pm CDST.
Yes it has..and this place is always going to be the crux of a lotta calamity..and when it counts,..I think we all will do fine again this season.
Were gonna have a lot going on.
And tonight I'll be the first to say Im gonna go the xtra mile to be civil.
Im a work in progress as well.
The Oil thing has been dicey for many here.
Sorry for getting snippy with you earlier. :)
Fugetaboutit..
I think you do fine cw.
I can be a jerk too,sometimes..
No doubt.
Well I am far away, but I feel the pain and I think I understand your emotion.. not thing I would wish on anyone at all.
What can I say....
I'm in Tampa and worried sick about it. I can't imagine being much closer to it.
Ocean Intervention III ROV 2
Nope not at all. Cold water in the mid-latitudes promotes net subsidence and focuses upward motion over the deep tropics. The subsidence over the central Atlantic also supports a Bermuda High farther southwest than normal, which helps direct storms more towards the Caribbean and United States. As a rule, hurricanes like to follow the heat (that is what they thrive on, after all), and when you outline a clear, easy path for them, they are likely to take it.
A graphic from my hurricane outlook:
I was thinking the same thing!
Thats one reason why I was wondering about the normal Florida rainy season setup.
ONWARD>>>>>>>>>
Patrick,how we got here at this minute does not matter. This has been a national crisis for sometime now.
I completely agree with you that we need more manpower, tankers (not a smaller version) skimming the surface, and a better, faster initiative. Hopefully, that is happening as I type.
We have assets available that for whatever reason, have not been pulled into the equation.
Nobody likes what has happened, Nobody. Let's hope we learn from this and our future remains positive.
Nature can surprise us sometimes. Look at the prior, much larger, leak near Mexico years ago.
Let's hope and pray things don't get worse and get better. At this point, we don't have many other options.
Positive thinking, can lead to positive results.
Make it so!
Thinking clean up or something like might be next after the Census. Got to pay my way but I'm a loose cannon right now. Point me at a good target and I'll go off. (Actually why I got tossed overboard at last gig. Great to have in a battle but dangerous in a storm. LOL)
BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE NEW ORLEANS LA
720 PM CDT THU JUN 3 2010
THE NATIONAL WEATHER SERVICE IN NEW ORLEANS HAS ISSUED A
* TORNADO WARNING FOR...
WESTERN ST. TAMMANY PARISH IN SOUTHEAST LOUISIANA...
THIS INCLUDES THE CITIES OF...MANDEVILLE...COVINGTON...
* UNTIL 800 PM CDT
* AT 716 PM CDT...NATIONAL WEATHER SERVICE METEOROLOGISTS DETECTED A
SEVERE THUNDERSTORM CAPABLE OF PRODUCING A WATERSPOUT OVER THE NORTH
PART OF LAKE PONTCHARTRAIN NEAR MANDEVILLE...MOVING NORTH AT 20 MPH.
* OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO
MADISONVILLE...ABITA SPRINGS...SUN AND BUSH
atmo: Looks like a non-threat on the scope, now, though.
(bolded locations should someone not recognize this is for their locale)
It now appears that the spinner over Houston will stay over land and move off to the northeast with time, but a piece of the upper trough may get left behind over the northwest gulf which could potentially try to cause mischief. This is not as favorable of a situation as it looked this morning, but should still be watched.
New Orleans, Base Reflectivity 0.50 Degree Elevation Range 248 NMI
Just because a show calls someone an expert doesn't mean their expertise applies to the situation.
Dr. Steiner is an 'expert' only as far as his field of study, which is marine biology, travels. He isn't a geologist nor a specialist in the fluid dynamics of an oil well.
Yes. Some thunderstorms and the intermittent threat of severe weather.
Other than that...not likely to pull a quick TC, in my opinion.
CATL Loop
Viewing: 1301 - 1351
Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 — Blog Index