TD 2 forms in the Atlantic; hundreds feared dead from Typhoon Morakot; Felicia hits

By: Dr. Jeff Masters , 1:55 PM GMT on August 11, 2009

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Tropical Depression Two has formed out of the strong tropical wave off the coast of Africa we've been watching, and has a good chance of becoming the Atlantic hurricane season's first named storm. Satellite loops of the storm show that heavy thunderstorm activity is increasing near the storm's center, and low-level spiral bands are getting better established. However, dry air to TD 2's north is interfering with this process, and the storm is being slow to organize. This morning's QuikSCAT pass missed TD 2.


Figure 1. Current satellite image of TD 2.

Wind shear over the storm is low, 5 knots, and is expected to remain low to moderate, 5 - 15 knots, through Thursday. Sea Surface temperatures are a marginal 26 - 27°C, and there is plenty of dry, stable air from the Saharan Air Layer (SAL) to to TD 2's north. The relatively cool SSTs and dry air mean that TD 2 will not be able to intensify quickly. However, does appear likely that TD 2 has enough going for it that it will be able to become Tropical Storm Ana later today or on Wednesday. Most of the computer models show some weak development, but none of them predict TD 2 will become a hurricane. It is unusual for storms forming this far north to make it all the way across the Atlantic to hit the Lesser Antilles Islands, and the current NHC forecast track aiming TD 2 north of the islands appears to be a good one.

Elsewhere in the Atlantic
Two other tropical waves, one passing through the Lesser Antilles Islands, and one about 600 miles east of the islands, are mentioned in NHC's Graphical Tropical Weather Outlook. Both of these waves have very limited heavy thunderstorm activity that is not increasing, and are not a threat to develop over the next two days. None of the computer models develop either of these waves.

A large, disorganized tropical wave is just leaving the coast of Africa, south of the Cape Verdes Islands. The GFS and ECMWF models continue to predict the possible development of this wave late this week.


Figure 2. Track and total rain amount from Typhoon Morakot. Image credit: NASA/GSFC.

Death toll from Typhoon Morakot in the hundreds
The death toll from Typhoon Morakot continues climb, as a landslide triggered by the storm's heavy rains hit the small town of Shiao Lin in southern Taiwan. Shiao Lin has a population of 1,300, and 400 - 600 people are missing in the wake of the landslide. Morakot killed an additional 41 elsewhere on Taiwan, with 60 missing. Earlier, the storm killed 22 in the Philippines, and went on to kill 6 in mainland China, which it hit as a tropical storm with 50 mph winds and heavy rain. Morakot's heavy rains caused an estimated $1.3 billion in damage to China.

Morakot moved very slowly as it passed over Taiwan, dumping near world-record amounts of rain. Alishan in the mountains of southern Taiwan recorded 91.98" of rain over a two-day period, one of the heaviest two-day rains in world history. The world 2-day rainfall record is 98.42", set at Reunion Island on March 15 - 17, 1952. Alishan received an astonishing 9.04 feet of rain over a 3-day period. The highest 1-day rainfall total ever recorded on Taiwan occurred Saturday at Weiliao Mountain in Pingtung County, which recorded 1.403 meters (4.6 feet or 55 inches) or rain. Nine the ten highest one-day rainfall amounts in Taiwanese history were reached on Saturday, according to the Central Weather Bureau.

Felicia continues to weaken, but is a flash flooding threat to Hawaii
Tropical Storm Felicia continues to steadily weaken, thanks to high wind shear of 30 knots. Recent satellite loops show that almost no heavy thunderstorm activity remains, and what little there is has been pushed to the northeast side of the center, exposing the surface center as a swirl of low clouds.


Figure 3. Tropical storm Felicia appeared as a swirl of low clouds with one spot of heavy thunderstorm activity to the northeast as it approached Hawaii yesterday evening.

High wind shear will continue to weaken Felicia today, and the storm is unlikely to cause major flooding problems as it moves over the islands today. The greatest danger of flooding will be over the northern islands, where Felicia's main moisture is concentrated.

Link to follow:
Wundermap for Hawaii

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I'll have an update Wednesday morning.

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Post 3385. Thanks, all that needs is a TD. Question for all. yellow means Tropical activity may start. TD meana tropical activity has started?
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Quoting rxse7en:
Yeah, I feel bad for those people in Fruiton. :D
\


LOL
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3404. IKE
Quoting Stormchaser2007:
Removed "some slow development" from the TWO


A LARGE AREA OF SHOWERS AND THUNDERSTORMS BETWEEN THE CAPE VERDE
ISLANDS AND AFRICA IS ASSOCIATED WITH A VIGOROUS TROPICAL WAVE.
SLOW DEVELOPMENT OF THIS SYSTEM IS POSSIBLE OVER THE NEXT FEW DAYS
AS IT MOVES TO THE WEST AT 10 TO 15 MPH. THERE IS A LOW CHANCE...
LESS THAN 30 PERCENT...OF THIS SYSTEM BECOMING A TROPICAL CYCLONE
DURING THE NEXT 48 HOURS.



If it developed quickly, odds are it would be a fish-storm.

One huge wave...may take time to really get going.
Member Since: June 9, 2005 Posts: 23 Comments: 37858
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The centre is still to the east of the convection but shear isn't toooo awful. 10-20kts is about marginal. Moving just south of due west at last extrapolation, but at only 12mph. So, not too fast that it runs away from the convection and can't stack itself right.

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Good morning all

Based upon the QS pass and the sat images it would appear that the COC with TD2 is very near the NE edge of the convection and at risk of exposure. This is a poorly organized TD with all the heavy convection off to the SW of the low center.
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3398. kdkinc
When a low just a low???

This time of year the GOM can erupt any time...
SO....
Just below Belize migrating north is that just more weather stuff or depression fuel
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Removed "some slow development" from the TWO


A LARGE AREA OF SHOWERS AND THUNDERSTORMS BETWEEN THE CAPE VERDE
ISLANDS AND AFRICA IS ASSOCIATED WITH A VIGOROUS TROPICAL WAVE.
SLOW DEVELOPMENT OF THIS SYSTEM IS POSSIBLE OVER THE NEXT FEW DAYS
AS IT MOVES TO THE WEST AT 10 TO 15 MPH. THERE IS A LOW CHANCE...
LESS THAN 30 PERCENT...OF THIS SYSTEM BECOMING A TROPICAL CYCLONE
DURING THE NEXT 48 HOURS.

Member Since: June 9, 2007 Posts: 4 Comments: 15718
Quoting Maverich:


Forgive the layman question. I am a lurker trying to make sense of the jargon u guys find so easy. Is Baje's arithmetic accurate to any degree? And what does it mean for 'Bill' and his small friend behind him?


Not perfect but very close.
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ADT still unimpressed. Scene type: Shear. Heh, that's a bit mean though.

Shear map:

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Quoting bajelayman2:


Noted. At 35W, I am at 59.4W. Thus, 59.4-35 = 14.6 times roughly 60miles = 876 miles to travel

Moving at say, 15 mph (guess), gives it (the centre) between 50 and 55 hours to get in this area.

That means that the overall system will begin affecting the area in roughly 2 days, which is Thursday.

Bye, I am off, have a good day.


Forgive the layman question. I am a lurker trying to make sense of the jargon u guys find so easy. Is Baje's arithmetic accurate to any degree? And what does it mean for 'Bill' and his small friend behind him?
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3393. rxse7en
Quoting Cotillion:


Yes, once.

1973, TS Christine.
Thanks, Cotillion. Googling now.
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Quoting sporteguy03:


It has happened before I think in October 2007 there were 5 circles once. Just means Atlantic is very active now.


Just posted it lol
Member Since: June 9, 2007 Posts: 4 Comments: 15718
Quoting sporteguy03:


Seems to be the thinking with many NWS offices if that is true someone might be dealing with a hurricane.


Yeah. Afraid so. :(
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3390. WxLogic
Quoting homegirl:


Ana?


In my eyes she has been ANA already... but I presume NHC is awaiting some additional consistency with this one.
Member Since: August 14, 2008 Posts: 4 Comments: 4881
I spent five years in PR. If your going to surf the NW shore in stormy weather you had best be VERY good. NO place for begginers.
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Quoting Autistic2:
I don't think I have ever seen three yellow and one TD w/o a named system before. Is this Normal?


It has happened before I think in October 2007 there were 5 circles once. Just means Atlantic is very active now.
Member Since: July 7, 2005 Posts: 0 Comments: 5120
3386. IKE
TROPICAL WEATHER OUTLOOK
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
800 AM EDT WED AUG 12 2009

FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...

THE NATIONAL HURRICANE CENTER IS ISSUING ADVISORIES ON TROPICAL
DEPRESSION TWO...LOCATED ABOUT 535 MILES WEST OF THE SOUTHERNMOST
CAPE VERDE ISLANDS.

A SMALL LOW OVER THE SOUTHEASTERN CARIBBEAN SEA IS PRODUCING A
LIMITED AREA OF SHOWERS AND THUNDERSTORMS. DEVELOPMENT OF
THIS SYSTEM IS NOT EXPECTED AND THERE IS A LOW CHANCE...LESS THAN
30 PERCENT...OF IT BECOMING A TROPICAL CYCLONE DURING THE NEXT 48
HOURS.

SHOWER ACTIVITY ASSOCIATED WITH A TROPICAL WAVE ABOUT 300 MILES EAST
OF THE LESSER ANTILLES HAS DIMINISHED. THERE IS A LOW CHANCE...
LESS THAN 30 PERCENT...OF THIS SYSTEM BECOMING A TROPICAL CYCLONE
DURING THE NEXT 48 HOURS.

A LARGE AREA OF SHOWERS AND THUNDERSTORMS BETWEEN THE CAPE VERDE
ISLANDS AND AFRICA IS ASSOCIATED WITH A VIGOROUS TROPICAL WAVE.
SLOW DEVELOPMENT OF THIS SYSTEM IS POSSIBLE OVER THE NEXT FEW DAYS
AS IT MOVES TO THE WEST AT 10 TO 15 MPH. THERE IS A LOW CHANCE...
LESS THAN 30 PERCENT...OF THIS SYSTEM BECOMING A TROPICAL CYCLONE
DURING THE NEXT 48 HOURS.

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.

$$
FORECASTER BEVEN
Member Since: June 9, 2005 Posts: 23 Comments: 37858
Quoting Autistic2:
I don't think I have ever seen three yellow and one TD w/o a named system before. Is this Normal?


This is nothing compared to this.

Member Since: June 9, 2007 Posts: 4 Comments: 15718
3384. WxLogic

Quoting sporteguy03:


Seems to be the thinking with many NWS offices if that is true someone might be dealing with a hurricane.


Having that consensus between NWS Offices definitely give more weight to ECMWF troughing than GFS sharp trough development... "B" could be causing chaos to everyone int he Greater Antilles to US.
Member Since: August 14, 2008 Posts: 4 Comments: 4881


Ana?
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Quoting rxse7en:
Based just on image alone, that looks like a TD over Africa. I had asked a while ago, but I was wondering if a TD has ever formed over Africa before entering the Atlantic. Anyone? And good morning. :D


1973 Christine

Member Since: June 9, 2007 Posts: 4 Comments: 15718
Quoting leftovers:
kind of looks like luis remember him but he curved out to sea


better start booking your flights to puerto rico and bringing the quiver...
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Quoting homelesswanderer:
NWS Lake Charles is not too impressed with anything. Not a mention of a trough, wave, anything. But they did say this fwiw

THE FRONT WILL GRADUALLY WASH OUT BY THE WEEKEND AS THE
BERMUDA HIGH BUILDS WEST.


Seems to be the thinking with many NWS offices if that is true someone might be dealing with a hurricane.
Member Since: July 7, 2005 Posts: 0 Comments: 5120
Quoting rxse7en:
Based just on image alone, that looks like a TD over Africa. I had asked a while ago, but I was wondering if a TD has ever formed over Africa before entering the Atlantic. Anyone? And good morning. :D


Yes, once.

1973, TS Christine.
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3378. IKE
South America view of the ECMWF.
Member Since: June 9, 2005 Posts: 23 Comments: 37858
I don't think I have ever seen three yellow and one TD w/o a named system before. Is this Normal?
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3376. rxse7en
Quoting Stormchaser2007:
Very broad low here.

Based just on image alone, that looks like a TD over Africa. I had asked a while ago, but I was wondering if a TD has ever formed over Africa before entering the Atlantic. Anyone? And good morning. :D
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Quoting Tropicsweatherpr:


In what latitud is the low forming?


18W, 11n

In that general vicinity.
Member Since: June 9, 2007 Posts: 4 Comments: 15718
3374. IKE
...ITCZ...

THE ITCZ AXIS IS CENTERED ALONG 12N14W 11N21W 12N27W...THEN
13N37W 11N48W 14N55W 12N62W THEN OVER NE VENEZUELA TO OVER
COLOMBIA AND E PANAMA INTO THE E PACIFIC REGION. JUST OF THE
COAST OF W AFRICA IS BROAD AREA OF SCATTERED MODERATE WITH
EMBEDDED CLUSTERS OF SCATTERED STRONG TO STRONG CONVECTION THAT
COVERS THE AREA FROM 7N-19N BETWEEN 18W-23W...WHICH COULD
POSSIBLY BE THE NEXT TROPICAL WAVE.
SMALL CLUSTERS OF SCATTERED
MODERATE TO ISOLATED STRONG CONVECTION ARE FROM 8N-10N BETWEEN
26W-36W.
Member Since: June 9, 2005 Posts: 23 Comments: 37858
Quoting WxLogic:


In my opinion... the only major difference would be the distance they affect a given area. Nor`Eastern are larger in scale than Hurricanes as the latter are more localized disturbances.

Of course as you know you have the core structure in which one is cold and the other one warm and so forth...

At a high level that's my take on it.


Alright, thanks. Just wondered as I've been in a few strong extratropical cyclones over time, thought the experience may or may not be different in some way.
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Quoting StormW:
06Z Model Guidance.

Top frame: Statistical

Bottom frame: Dynamic








consensus on bringing it close to the pr north coast... hopefully large and still powerful enough to generate groundswell.

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3371. rxse7en
Quoting Stormchaser2007:
I cannot even begin to express how strong this would be if it came to fruiton.

6z
162hours
Yeah, I feel bad for those people in Fruiton. :D
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Very broad low here.

Member Since: June 9, 2007 Posts: 4 Comments: 15718
Ike from Melbourne Discussion AM:

Sun-Tue...strong dlm ridging will remain anchored north of Florida into
the xtd...with perhaps just a slight weakening by Tuesday. This will hold
deep layer easterlies in place with sufficient moisture to produce
isolated-scattered late morning-early afternoon convection near the coast and mainly
afternoon rain showers/ts inland. While the GFS suggests that we may be dealing
with the approach of whatever is left of T.D. #2 in one form or
another by the middle of next week...the new ecm is quite a bit
slower and father north. In any event we have at least a full week
to keep an eye out to the east.
Member Since: July 7, 2005 Posts: 0 Comments: 5120
3368. IKE
Large wave emerging off of Africa.....

Member Since: June 9, 2005 Posts: 23 Comments: 37858
NWS Lake Charles is not too impressed with anything. Not a mention of a trough, wave, anything. But they did say this fwiw

THE FRONT WILL GRADUALLY WASH OUT BY THE WEEKEND AS THE
BERMUDA HIGH BUILDS WEST.
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good morning all neeed coffee
WOW one TD three yellow and yet the 0-0-0 lives? WTF
Could my 5-2-0 from June first really happen?
I said first named storm Sept 2 but...........
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3364. WxLogic
006Z NOGAPS finally in line... and keeping a live an kicking long enough to do some "spring" cleaning.

Also... latest QS (tight circulation, just needs to build some extra convection to its E):

Member Since: August 14, 2008 Posts: 4 Comments: 4881
You can see the center now starting to come out at about 33W 14N.


Member Since: June 9, 2007 Posts: 4 Comments: 15718
456,in what latitud you look for a low to form with wave off Africa? I ask because depending on the latitud,we in the Caribbean may get or not a landfall.I am in PR.
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Quoting futuremet:
Um...err..456




wow
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Quoting IKE:


Odds are their overdoing it.




Thank you Ike.
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Tropical Depression #2 may end up being the sacrificial lamb for the western African disturbance. TD 2 may end up moistening up the environment, sweeping out dry Saharan air and creating a very favorable environment for this disturbance. So, it is probably a good idea to monitor this particular disturbance very closely over the coming days.

Nice.. one lol

By Rob from crownwx
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Off to work now.

Have a good day everybody.
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About JeffMasters

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