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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Quoting Stormchaser2007:


It should be classified by 11pm.


Thanks.
Member Since: August 2, 2006 Posts: 0 Comments: 1240
Quoting StSimonsIslandGAGuy:
Last year the ECMWF was not conservative. At all. It kept developing Typhoon Tip type storms east of the Bahamas. It was so crazy I put a T behind the F in the model :)


:/

Also, 1000mb - 45kt is TS strength right?
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Quoting alaina1085:
So does TD2 have everything it needs to be classified as Ana? It doesnt "look" like a TS but looks can be deceiving.


It should be classified by 11pm.
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2101. aquak9
Quoting srada:
Good evening everyone!

Local Mets here in Wilm, NC are all on the bandwagon and they are mostly concerned with the second wave behind TD2..should be an interesting next couple of weeks!


See what I mean?
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Quoting weathersp:
HMMM.....

Its taking a while for that 8PM TWO...


Its already out
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2099. IKE
Member Since: June 9, 2005 Posts: 23 Comments: 37858
TD is still looking rather ragged at this point. Deep convection has developed nearer teh center, but whether or not it will sustain itself is questionable.

The wave exiting the African coast has a MASSIVE envelope. One to watch most certainly.
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2096. aquak9
Quoting reedzone:
Evening guys, looks l2 is bound to be Ana by looking at the latest Dvorak T-numbers. We'll see though. Local meteorologists here are now telling us to closely watch the wave off of Africa behind TD2. I will make a diagram and report on where and what this "potential" historic storm could do. Not a prediction, but possibilities by looking at the models and future conditions.


Reedzone, just been lurking a while, but seems like everyone's saying the same thing "local mets are saying watch the next wave just now emerging"

certainly we all don't live in the same area...are ALL the local mets across the southeast saying this? That sounds,(pulls out thesaurus) err..precipitously ominous... (puts away thesaurus)
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So does TD2 have everything it needs to be classified as Ana? It doesnt "look" like a TS but looks can be deceiving.
Member Since: August 2, 2006 Posts: 0 Comments: 1240
2094. srada
Good evening everyone!

Local Mets here in Wilm, NC are all on the bandwagon and they are mostly concerned with the second wave behind TD2..should be an interesting next couple of weeks!
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2092. Patrap
OuikSCAT Page,one to Bookmark
Member Since: July 3, 2005 Posts: 415 Comments: 125711
Quoting Drakoen:
ECMWF bombing out system is no surprise if conditions are favorable.


vigorous wave at a nice latitude.
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Quoting weathersp:
HMMM.....

Its taking a while for that 8PM TWO...

LOL

It came out a half hour ago.
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HMMM.....

Its taking a while for that 8PM TWO...
Member Since: January 14, 2007 Posts: 17 Comments: 4140
SSTs are supportive of a major hurricane WS. Upper level influences will not be known until later, of course.
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Quoting Acemmett90:
ANA is waking up from her nap and she is pissed

Lol, so true.
Member Since: February 21, 2008 Posts: 1 Comments: 340
Quoting StormSurgeon:


Are you sure that won't be Claudette?


We need Ana first.

The 53W wave wont become Bill before the EATL wave.
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Quoting Weather456:


Thanks
Has the 2nd wave fully emerged off the coast yet ?
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Evening guys, looks like TD2 is bound to be Ana by looking at the latest Dvorak T-numbers. We'll see though. Local meteorologists here are now telling us to closely watch the wave off of Africa behind TD2. I will make a diagram and report on where and what this "potential" historic storm could do. Not a prediction, but possibilities by looking at the models and future conditions.
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Quoting Weather456:


That's what got me scratching my head. Why did the ECMWF have such a bomb.


So, do you guys predict a more southerly tract? Or north as some of the models are showing?
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Quoting Acemmett90:
ANA is waking up from her nap and she is pissed

UW-CIMSS Automated Satellite-Based
Advanced Dvorak Technique (ADT)
Version 7.2
Tropical Cyclone Intensity Estimation Algorithm


Current Intensity Analysis




UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 7.2.3
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 11 AUG 2009 Time : 231500 UTC
Lat : 14:36:39 N Lon : 30:47:09 W


CI# /Pressure/ Vmax
3.0 /1000.0mb/ 45.0kt


Final T# Adj T# Raw T#
(3hr avg)
3.0 3.2 3.2

Latitude bias adjustment to MSLP : +0.0mb

Center Temp : -2.4C Cloud Region Temp : -21.3C

Scene Type : SHEAR (0.18^ TO DG)

Positioning Method : FORECAST INTERPOLATION

Ocean Basin : ATLANTIC
Dvorak CI > MSLP Conversion Used : ATLANTIC

Tno/CI Rules : Constraint Limits : NO LIMIT
Weakening Flag : OFF
Rapid Dissipation Flag : OFF


Been watching the estimates come in throughout the afternoon and am surprised that they have continued to increase. Don't know whats going on with the ADT, but it just seems somewhat off.
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2067. serialteg 11:55 PM GMT on August 11, 2009
Quoting Nolehead:
2032. serialteg

lucky dog.....


i know! :D :D :D :D :D :D im as giddy as a kid thrown into a toys r us spree... i know its just models but...

can someone please link me up to the ECMWF forecasts so i can see them? since google and i have epic failed at this tonight XD


Link
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Quoting Vortex95:


I'm hoping you do know that when cloud tops cool convection increases?


wow...its been one of those days...i wanted to apologize to you....i completely misread your original post...and im sorry...
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Quoting Stormchaser2007:
As StormW mentioned...there is a developing anticyclone over the "Bill" wave.


Are you sure that won't be Claudette?
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2076. Drakoen
Quoting StSimonsIslandGAGuy:
Last year the ECMWF was not conservative. At all. It kept developing Typhoon Tip type storms east of the Bahamas. It was so crazy I put a T behind the F in the model :)


Exactly
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WS, simply put, the potential for a storm to bomb out north of the islands, on the way to the Bahamas is an absolute "yes". The question is... will it? (and nobody knows that answer)
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2074. Drakoen
ECMWF bombing out system is no surprise if conditions are favorable.
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2071. Patrap
Navy/NRL Tropical Cyclone Page
Member Since: July 3, 2005 Posts: 415 Comments: 125711
Quoting WeatherStudent:



Ooohhhh, so that's how you could tell, huh? Interesting....although, God forbid, can it become that strong?

If upper-air conditions are right (little to no shear, good outflow), then absolutely.
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Ana, think you can do something about this?

POOR
SURF: 1-2 ft - ankle to knee high and poor conditions. POOR
SURF: 1-2 ft - ankle to knee high and poor conditions. POOR
SURF: 1-2 ft - ankle to knee high and poor conditions. To see five days of forecast data, become a premium subscriber. To see five days of forecast data, become a premium subscriber.
SW/SSW windswell/chop and SE background swell mix
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As StormW mentioned...there is a developing anticyclone over the "Bill" wave.
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Quoting Nolehead:
2032. serialteg

lucky dog.....


i know! :D :D :D :D :D :D im as giddy as a kid thrown into a toys r us spree... i know its just models but...

can someone please link me up to the ECMWF forecasts so i can see them? since google and i have epic failed at this tonight XD
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2065. java162
Quoting jurakantaino:

The one behind. Glad that it seems to lose his punch just before crossing Puerto Rico,,,


what are you talking about????
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Quoting SouthALWX:

Um. I get what your doing .. but isn't a one word "flagged" post as bothersome as the original? Or asbothersome as this post complaining that post for that matter? I'm just sayingh is it necessary to say " I called the law on you" rather than just to do it ..


i completely understand what your saying...i only do it from time to time, the whole flagged thing....but not again...only in the background where no one can see or be bothered by it...i promise...
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Great timing Pat.
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Quoting Weather456:


That's what got me scratching my head. Why did the ECMWF have such a bomb.
weather god for bid that monster does not come near any land area
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Quoting Weather456:


my God

Pretty close to my sentiments. The biggest question marks are going to be upper-air conditions and track. The waters are plenty warm enough, and TCHP is ripe.
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Quoting Weather456:


That's what got me scratching my head. Why did the ECMWF have such a bomb.


Trust your education and instincts.
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2059. Patrap
Hurricane preparation Entry
Member Since: July 3, 2005 Posts: 415 Comments: 125711
Quoting jasoniscoolman10:


Thanks
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Evening Weatherstudent
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Quoting KmanGal:


West Bay, Grand Cayman. Yours?
East End
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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.