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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1456. HadesGodWyvern (Mod)
METEO France
High Sea Warning

TROPICAL DEPRESSION ( NR 2 ), 1006 NEAR 14.5N 28.5W, MOVING WEST.
EXPECTED TROPICAL STORM NEAR 14.8N 33.6W BY 12 AT 12 UTC,

Outlook
14.9N 35.8W BY 13 AT 00 UTC.
Member Since: Posts: Comments:
Quoting TampaHelpDesk:


That's an impressive burst about to come off the coast. Not an expert on weather though... is that a common occurrence this time of year?
UH, very common
Member Since: Posts: Comments:
Quoting wunderkidcayman:
UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 7.2.3
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 11 AUG 2009 Time : 194500 UTC
Lat : 14:41:24 N Lon : 30:27:35 W


CI# /Pressure/ Vmax
2.6 /1004.0mb/ 37.0kt


Final T# Adj T# Raw T#
(3hr avg)
2.6 2.8 3.4

Latitude bias adjustment to MSLP : +0.0mb

Center Temp : -3.7C Cloud Region Temp : -29.6C

Scene Type : SHEAR (0.04^ TO DG)

Positioning Method : FORECAST INTERPOLATION

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

Tno/CI Rules : Constraint Limits : 1.2T/6hr
Weakening Flag : OFF
Rapid Dissipation Flag : OFF

hmmm
is that for TD 2
Member Since: Posts: Comments:
Quoting TampaHelpDesk:


That's an impressive burst about to come off the coast. Not an expert on weather though... is that a common occurrence this time of year?


Yes.
Member Since: Posts: Comments:
UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 7.2.3
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 11 AUG 2009 Time : 194500 UTC
Lat : 14:41:24 N Lon : 30:27:35 W


CI# /Pressure/ Vmax
2.6 /1004.0mb/ 37.0kt


Final T# Adj T# Raw T#
(3hr avg)
2.6 2.8 3.4

Latitude bias adjustment to MSLP : +0.0mb

Center Temp : -3.7C Cloud Region Temp : -29.6C

Scene Type : SHEAR (0.04^ TO DG)

Positioning Method : FORECAST INTERPOLATION

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

Tno/CI Rules : Constraint Limits : 1.2T/6hr
Weakening Flag : OFF
Rapid Dissipation Flag : OFF

hmmm
Member Since: Posts: Comments:
Quoting P451:
WV, 21hr Loop, ending 19Z



That's an impressive burst about to come off the coast. Not an expert on weather though... is that a common occurrence this time of year?
Member Since: August 28, 2008 Posts: 0 Comments: 65
1450. HadesGodWyvern (Mod)


..and look there is a low in the southern hemisphere =P
Member Since: Posts: Comments:
Quoting mikatnight:


Hi Aggie -
Not trying to be obtuse, but I thought that was TD2, and not the wave following it (to the SW). Or did I miss something completely?


No problem with good questions, here. Go look at the animation step by step (by hitting the +1) and you will see that GFS does about nothing with our TD2 friend and develops the following wave rather thoroughly.
http://moe.met.fsu.edu/cgi-bin/gfstc2.cgi?time=2009081112&field=Sea+Level+Pressure&hour=Animation
Member Since: Posts: Comments:
Quoting hurricane23:
Once again the GFS nails miami on 8-24...We'll see.


Its pretty funny. 8-24, the "A" storm, blah blah blah. Love those long range models
Member Since: May 17, 2009 Posts: 0 Comments: 559
Quoting foggymyst:
Thanks CaneWarning. How about the one ahead of that one? Just heard local news that it should stay a wave and bring rain to south fla.


Tampa news is calling for increased rain chances this weekend due to one of the waves.
Member Since: Posts: Comments:
Quoting atmoaggie:

How about now?


Man do we need some better cyclogenesis models.


Hi Aggie -
Not trying to be obtuse, but I thought that was TD2, and not the wave following it (to the SW). Or did I miss something completely?
Member Since: Posts: Comments:
1444. HadesGodWyvern (Mod)
Japan Meteorological Agency

Tropical Disturbance Summary (1800z 11AUG)
=========================================

At 3:00 AM JST, Low Pressure Area (1008 hPa) located at 13.0N 130.0E is reported as moving west-northwest slowly
Member Since: Posts: Comments:
Thanks CaneWarning. How about the one ahead of that one? Just heard local news that it should stay a wave and bring rain to south fla.
Member Since: Posts: Comments:
Quoting foggymyst:
Been lurking on and off since yesterday. As per Florida, the first wave is the one to watch..as of now. Am I correct? Would anyone know the time frame of potential effect? Thanks.


I'm no expert, but check out the Weather Underground Tropical Weather page and scroll down to the "GFS model, Atlantic (WU)"
Member Since: Posts: Comments:
Oh, by the way I just watched a special on what a cat 5 would do to Miami on the weather channel. At least 1 million homeless no way to plan for that mess was everyone's opinion. I would say this if se fl dade broward line gets hit by a cat5, forget national health insurance we will have national home insurance first or that will be the straw that breaks the economies back. Then they followed it up with tropical update very weak. Boy I can remember when the channel was about weather.
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Quoting mikatnight:


I don't see it.



The GFDL isn't designed to pick up new systems like the ECMWF or the GFS does. It focuses on 1 storm (in this case TD 2).
Member Since: Posts: Comments:
Quoting mikatnight:


I don't see it.


How about now?


Man do we need some better cyclogenesis models.

GFDL and HWRF are not for genesis of a new system. They just don't do that.
Member Since: Posts: Comments:
Quoting atmoaggie:


The more I look, the more I think that TD2 is a non-threat...just a distraction, from the next one. A real system of concern may be pending and TD2 is not it.


you may be right. Conditions seem to be perfect for this big one to come off at a low lat.



Link
Member Since: Posts: Comments:
Quoting foggymyst:
Been lurking on and off since yesterday. As per Florida, the first wave is the one to watch..as of now. Am I correct? Would anyone know the time frame of potential effect? Thanks.


2 weeks
Member Since: Posts: Comments:
Been lurking on and off since yesterday. As per Florida, the first wave is the one to watch..as of now. Am I correct? Would anyone know the time frame of potential effect? Thanks.
Member Since: Posts: Comments:
Quoting winter123:
Anyone else looking at this thing? (center)



vis loop

I can't get a high enough resolution image, but if you look at a visible you can see a well defined, but extremely small surface low. This has been moving WSW since yesterday so I think it may even landfall on SA before it has a chance. Still, it's interesting because if it forms it will break Marco's smallest size record.
Member Since: Posts: Comments:
Quoting atmoaggie:


The more I look, the more I think that TD2 is a non-threat...just a distraction, from the next one. A real system of concern may be pending and TD2 is not it.


I don't see it.

Member Since: Posts: Comments:
1430. Patrap
Your seeing the Climatology catching up to the Basin Chicklit,..and we've reached a tipping point throughout it seems.

I urge everyone to finish your Prep Kits and have your supplies readied for the Frays to come.

















Member Since: July 3, 2005 Posts: 428 Comments: 129904
Quoting Stormchaser2007:
Ill be back later.


Cya!
Member Since: Posts: Comments:
IMO, TD 2 will be at 35mph at 5pm and possibly TS Ana at 11pm or sometime tommorow morning.
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Quoting sullivanweather:
The last several nights there's been big time flare ups of convection during diurnal max with the newly formed TD#2. I fully expect this to occur once again tonight and the end result being TD#2 becoming Ana.


You know what... I am not so sure its the DMAX...

Look at this loop:
http://cimss.ssec.wisc.edu/tropic/real-time/tpw2/natl/main.html

Everytime a point goes around the sprial and hits the ITCZ it flares up.. Its constant too, ever since africa... Now unless 1 revolution is exactly a 24hr cycle and coincides with DMAX and ITCZ I think its the ITCZ thats giving it energy... Note how it fades as soon it hits dust in the North side of the low..
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Quoting CaneWarning:


What is that on the west coast of Florida?


Sorry, SE of Td2
Member Since: July 24, 2005 Posts: 407 Comments: 19076
Anyone else looking at this thing? (center)



Link

I can't get a high enough resolution image, but if you look at a visible you can see a well defined, but extremely small surface low. This has been moving WSW since yesterday so I think it may even landfall on SA before it has a chance. Still, it's interesting because if it forms it will break Marco's smallest size record.
Member Since: Posts: Comments:
Ill be back later.
Member Since: Posts: Comments:
1423. Skyepony (Mod)
I think a better way to explain DMAX is during the day the sun shines & heats the air hotter than the water, this warms cloud tops many times limiting convection. The hottest time of the afternoon is DMin. At night, no sun, the air cools quickly but the water holds it's heat. The air directly over the water is warmed by the water, hotter than the air above it, so this begins to rise creating an unstable enviroment. As the damp warm air from close to the sea rises in the cool night air it too is cooled til it's the same temp as the air above, also it's water condenses on the rise somewhere along the way creating convection. Right before sunrise, usually night air is at it's coolest, this is DMax, when the atmosphere is most unstable.
Member Since: Posts: Comments:
Quoting jeffs713:

No kidding. It won't take traveling over the loop current... It just has to enter the GOM.


Take a look at the link on post 1388.
Does mention something about the GOM....
Member Since: Posts: Comments:
1421. Patrap
Member Since: July 3, 2005 Posts: 428 Comments: 129904
UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 7.2.3
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 11 AUG 2009 Time : 194500 UTC
Lat : 14:41:24 N Lon : 30:27:35 W


CI# /Pressure/ Vmax
2.6 /1004.0mb/ 37.0kt


Final T# Adj T# Raw T#
(3hr avg)
2.6 2.8 3.4

Latitude bias adjustment to MSLP : +0.0mb

Center Temp : -3.7C Cloud Region Temp : -29.6C

Scene Type : SHEAR (0.04^ TO DG)

Positioning Method : FORECAST INTERPOLATION

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

Tno/CI Rules : Constraint Limits : 1.2T/6hr
Weakening Flag : OFF
Rapid Dissipation Flag : OFF

****************************************************


History File Listing
Satellite Imagery (JAVA movie)
Time Series

Experimental Wind Field Product
McIDAS | MATLAB
Member Since: Posts: Comments:
Quoting Patrap:
C Atlantic IR loop







The little wave that was near Barbados seems to be trying to flare a bit again today. It looks like it might be eventually scooped up by the larger wave to it's east though.
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Quoting Weather456:
12Z GFDL also show a strong system SW of TD 2 in 126 hrs





The more I look, the more I think that TD2 is a non-threat...just a distraction, from the next one. A real system of concern may be pending and TD2 is not it.
Member Since: Posts: Comments:
Quoting atmoaggie:

Maybe they don't hit the whole distribution list at once...I didn't yet get that message.


NWS Status Message

http://weather.noaa.gov/tgstatus/
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1416. Patrap
Member Since: July 3, 2005 Posts: 428 Comments: 129904
Quoting CycloneOz:
Gee-mon-eez!

The Gom is a seething cauldron of hot water and water vapor.

My God, if anything gets in there...


No kidding. It won't take traveling over the loop current... It just has to enter the GOM.
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the tropical wave to the se of TD 2 looks large looks like this may be our next player
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Quoting WxLogic:


That's the wave currently @55W


Eeeek.
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Yeah 456 I believe thats the wave thats currently around 53W. It will be interesting if that wave develops what effects it will have on the steering of the other two storms behind it.
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1410. WxLogic
Quoting CaneWarning:


What is that on the west coast of Florida?


That's the wave currently @55W
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Quoting Seflhurricane:
dont even mention a storm to head for the gulf Gas prices are High Enough and the gulf coast is still busted up
Amen to that...We surely don't need anything coming our way nor does anyone else.
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Quoting Acemmett90:
yah that was not cool that was a low blow for us in south florida


And I'm right here in Ft. Lauderdale...... Dont' need a repeat of that year
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1406. Patrap
C Atlantic IR loop





Member Since: July 3, 2005 Posts: 428 Comments: 129904

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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.

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