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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5 days

Member Since: July 24, 2005 Posts: 407 Comments: 19076
1355. WxLogic
Quoting CybrTeddy:


They'll most likely bump it up to 35 MPH.


Hope you're not interpreting the 35KTS as 35MPH... :)
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Quoting mrnicktou:


Thanks again!




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Quoting FLGatorCaneNut:


Happy 17th anniversary
'

Ugh...
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Quoting Claudette1234:
well next advice to named ANA

35knots=40mph


No Ana at 5pm...

Assuming NRT doesnt have any renumbers to post.
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Quoting hurricane23:
Once again the GFS nails miami on 8-24...We'll see.


Happy 17th anniversary
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Quoting CybrTeddy:


They'll most likely bump it up to 35 MPH.


Most likely. If we see another track shift south then the intensity forecast should show a stronger system.
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1347. Patrap
GOES-12 Atmospheric Imagery

These images are primarily for use in tropical storm monitoring. There are several areas to choose from providing a large-scale view of the Atlantic, down to the Gulf of Mexico. During hurricane season, the hurricanes page provides a variety of GOES atmospheric products to help monitor the active storms
Member Since: July 3, 2005 Posts: 415 Comments: 125753
well next advice to named ANA

35knots=40mph
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Quoting CaneWarning:


Andrew #2

Oh don't EVEN go there...please
Member Since: September 5, 2007 Posts: 0 Comments: 3480
Quoting fmbill:


LOL!!! We just got the 12z run!

Actually, I'm waiting for the 00z run. (Mostly because I'll be home on the computer then)


Well the 18z is important to me becuase I need to know how the "extra" energy will play a role in this waves potential development.
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Quoting Stormchaser2007:
Its a nice improvement but the Satellite appearance is ragged.

CI# /Pressure/ Vmax
2.5 /1005.0mb/ 35.0kt




They'll most likely bump it up to 35 MPH.
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UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 7.2.3
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 11 AUG 2009 Time : 191500 UTC
Lat : 14:41:04 N Lon : 30:21:55 W


CI# /Pressure/ Vmax
2.5 /1005.0mb/ 35.0kt


Final T# Adj T# Raw T#
(3hr avg)
2.5 2.8 3.3

!!!!????!!!!
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Quoting Drakoen:


That's interesting. Thanks for always keeping up to date with the models and their upgrades


The full details from email:

"NCEP WILL BE CONDUCTING A LIVE PRODUCTION RUN FROM THE CIRRUS SUPERCOMPUTER FOR THIS UPCOMING /4 AUG/ PROD CYCLE PER SCHEDULE BELOW. PRODUCTION WILL RETURN TO DEW FOR
TODAYS 18Z CYCLE.

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

THE NEW NOAA NWS NCEP SUPERCOMPUTERS...STRATUS/CIRRUS... ARE SCHEDULED TO BECOME OPERATIONAL IN AUGUST.
NCEP/NCO WILL BE PERFORMING TESTS DURING THE NEXT SEVERAL WEEKS IN ORDER TO ENSURE THAT PRODUCT DELIVERY IS NOT IMPACTED ON THE IMPLEMENTATION DATE. NCEP/NCO IS PLANNING
TO DISSEMINATE PRODUCTS OPERATIONALLY FROM CIRRUS AND STRATUS ON THE DATES LISTED BELOW:

CIRRUS - 12Z CYCLE TUE AUG 4TH...ONE CYCLE ONLY
STRATUS - 12Z CYCLE MON AUG 10TH...ONE CYCLE ONLY
IMPLEMENTATION DATE: 12Z CYCLE TUE AUG 18TH

AS WITH PREVIOUS UPGRADES...THE MODEL FORECASTS FROM THE NEW COMPUTER MAY BE DISCONTINUOUS FROM THOSE PRODUCED ON THE OLD COMPUTER/PREVIOUS CYCLE ESPECIALLY AFTER DAY 5. WHY? THE HARDWARE/COMPILERS USED BY THE TWO COMPUTERS DIFFER AND THE DATA DECODERS/ASSIMILATION SYSTEMS HAVE BEEN RUNNING INDEPENDENTLY ON EACH SYSTEM. THESE TWO FACTORS WILL CREATE SMALL DIFFERENCES IN MODEL INITIAL CONDITIONS CAUSED BY ASSIMILATING DIFFERENT AMOUNTS OF DATA AND USING SLIGHTLY DIFFERENT FIRST GUESS FIELDS. SMALL NON-METEOROLOGICAL DIFFERENCES EVOLVE QUICKLY INTO RANDOM NOISE - TRIGGERING CONVECTION IN DIFFERENT LOCATIONS AT DIFFERENT TIMES. THESE TYPES OF DIFFERENCES GROW QUICKLY AND TEND TO SATURATE AFTER A FEW HOURS OF MODEL TIME. AVERAGED OVER A LARGE NUMBER OF CASES THERE IS NO EVIDENCE THAT ONE MACHINE IS BETTER THAN THE OTHER...OR DIFFERENT IN ANY OTHER SYSTEMATIC WAY.

EMC HAS BEEN MONITORING THE MODEL SUITE RUNNING ON THE NEW COMPUTER AND RESULTS HAVE SHOWN THAT THERE IS NO APPRECIABLE DIFFERENCE IN SKILL SCORE BETWEEN THE SYSTEMS. THIS IS TO BE EXPECTED SINCE THE MODELING SUITE HAS NOT CHANGED.
WE APOLOGIZE FOR ANY INCONVENIENCES THIS MAY CAUSE. ALSO... THE SCHEDULE IS HIGHLY SUBJECT TO CHANGE IN THE EVENT OF A CRITICAL WEATHER DAY DURING THE TEST PERIOD. WE WILL STRIVE TO INFORM USERS AS SOON AS POSSIBLE IN THE EVENT OF ANY SCHEDULE CHANGES. "
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Hurricane Donna (1960)

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1337. fmbill
Quoting Stormchaser2007:
It will be interesting to see what the 18z GFS will do with the energy over Africa.



LOL!!! We just got the 12z run!

Actually, I'm waiting for the 00z run. (Mostly because I'll be home on the computer then)
Member Since: Posts: Comments:
Its a nice improvement but the Satellite appearance is ragged.

CI# /Pressure/ Vmax
2.5 /1005.0mb/ 35.0kt


Member Since: Posts: Comments:
Quoting Stormchaser2007:


Click TD2 and scroll down to 18Z



Thanks again!
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Quoting gator23:

i lived through Andrew too. Drop it all you want im not biting.


I'm saying the models show the potential for it. Ah whatever. I won't argue.
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This waves latitude is great for a long tracker,nothing to get worked up about just something to moniter as the ECM/GFS both bring a signifcant cyclone in the general direction of the eastcoast.As always it will all come down to timeing.
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 : 191500 UTC
Lat : 14:41:04 N Lon : 30:21:55 W


CI# /Pressure/ Vmax
2.5 /1005.0mb/ 35.0kt


Final T# Adj T# Raw T#
(3hr avg)
2.5 2.8 3.3

Member Since: Posts: Comments:
Quoting mrnicktou:


Where did you get the 18z model at?


Click TD2 and scroll down to 18Z

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Quoting CybrTeddy:


Yea, a shift to the south not surprising.


Where did you get the 18z model at?
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It will be interesting to see what the 18z GFS will do with the energy over Africa.

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1325. gator23
Quoting CaneWarning:


I lived Andrew so I will drop it when I want to. Notice the date.

i lived through Andrew too. Drop it all you want im not biting.
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Quoting hurricane23:
Once again the GFS nails miami on 8-24...We'll see.
i hope not we do not need a hurricane here in florida we are hanging by a tread with insurance if we get nailed we are going to take a dump real bad
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Quoting Stormchaser2007:


18z



Yea, a shift to the south not surprising.
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Quoting gator23:

dont drop the A-word. too early.


I lived Andrew so I will drop it when I want to. Notice the date.
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Quoting Seflhurricane:
thanks looks like this MAY POSSIBLY be a problem for the northern lesser antilies but it is still far way in time to know


Exactly.
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Still kind of iffy with the "Bill" wave. The next 24 hours will be crucial.

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1318. gator23
Quoting CaneWarning:


Andrew #2

dont drop the A-word. too early.
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Quoting Stormchaser2007:


No this is TD2

This is a large shift south.
thanks looks like this MAY POSSIBLY be a problem for the northern lesser antilies but it is still far way in time to know
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1316. gator23
Quoting CycloneOz:
Typical Blog Postings When Tropical Activity is Occurring.

1) When there is yet to be an invest

a. "{Next Storm Name} is going to hit Florida!"
b. "This one's a fish."
c. "How can you give it a name? It's not even an invest!"
d. "Looks like it's going to be a Cat V!"


2) When there is an invest

a. "{Next Storm Name} is going to hit Florida!"
b. "This one's a fish."
c. "How can you give it a name? It's only an invest!"
d. "Looks like it's going to be a Cat V!"

and on and on...

You forgot
When There is Hurricane
a."{Next Storm Name} is going to hit Florida!
b. "This one's a fish.
c. "How can you give it a name? It's only an invest!"(some people can be really confused)
d. "Looks like it's going to be a Cat V!"
Member Since: Posts: Comments:
That annoying eastern Caribbean disturbance is producing heavy convection again this afternoon. It seems to have real trouble maintaining those cloud tops for more than a few hours before diminishing. The wave behind it, approaching the antilles, continues to improve in terms of structural organization, and is developing slightly more thunderstorm activity
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Quoting hurricane23:
Once again the GFS nails miami on 8-24...We'll see.


Andrew #2
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1313. Patrap
Member Since: July 3, 2005 Posts: 415 Comments: 125753
Quoting mrnicktou:


Thank You very much!


No problem.
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Once again the GFS nails miami on 8-24...We'll see.
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1310. IKE
PROGNOSTIC DISCUSSION FOR 6 TO 10 AND 8 TO 14 DAY OUTLOOKS
NWS CLIMATE PREDICTION CENTER CAMP SPRINGS, MD
300 PM EDT TUE AUGUST 11 2009

6-10 DAY OUTLOOK FOR AUG 17 - 21 2009

TODAY'S NUMERICAL MODELS ARE IN FAIR AGREEMENT ON THE PREDICTED 500-HPA
CIRCULATION PATTERN OVER NORTH AMERICA DURING THE 6-10 DAY PERIOD. TODAY'S
FORECAST FEATURES A MEAN TROUGH OVER THE ARCTIC EXTENDING TO ALASKA AND THE
NORTHERN PACIFIC, WITH ANOTHER MEAN TROUGH OVER THE EASTERN ATLANTIC OCEAN.
TODAY'S OPERATIONAL 00Z AND 06Z GFS PREDICTS A RIDGE OVER THE SOUTHEASTERN
CONUS, ANOTHER RIDGE NEAR THE ALASKA PANHANDLE AND WEST COAST OF THE CONUS, AND
A TROUGH OVER EASTERN CANADA EXTENDING TO THE NORTHERN ROCKIES. THE RIDGE NEAR
THE WEST COAST OF THE CONUS IS FORECAST CLOSER TO THE COAST BY THE GFS
ENSEMBLES THAN BY THE CANADIAN ENSEMBLES, AND THE RIDGE IS STRONGER IN THE GFS
ENSEMBLES THAN IN THE CANADIAN ENSEMBLES. THE OFFICIAL FORECAST IS COMPRISED
LARGELY OF A BLEND OF THE GFS-BASED SOLUTIONS. ENHANCED PROBABILITIES FOR ABOVE
NORMAL TEMPERATURES ARE INDICATED FOR THE EAST AND WEST COASTS OF THE CONUS,
WHILE COOLER THAN NORMAL CONDITIONS ARE FAVORED FOR THE SOUTHERN PLAINS. WETTER
THAN NORMAL CONDITIONS ARE FAVORED FOR THE MIDDLE ATLANTIC AND PARTS OF
SOUTHEAST. WETTER THAN NORMAL CONDITIONS ARE ALSO EXPECTED FOR PARTS OF THE
CENTRAL AND SOUTHERN ROCKIES DUE TO THE MONSOON ACTIVITY. THE FORECAST RIDGE
OVER THE WEST COAST OF THE CONUS FAVORS DRIER THAN NORMAL CONDITIONS FOR THE
WEST COAST OF THE CONUS.


8-14 DAY OUTLOOK FOR AUG 19 - 25 2009

TODAYS GFS-BASED ENSEMBLE MEANS ARE IN GOOD AGREEMENT IN DEPICTING A STRONG
TROUGH NEAR THE EASTERN CONUS AND A RIDGE NEAR THE WESTERN CONUS. THE
OPERATIONAL 0Z AND 6Z GFS ARE IN GOOD AGREEMENT WITH EACH OTHER AND GENERALLY
REFLECT THE SAME FEATURES AS THEIR RESPECTIVE ENSEMBLE MEANS. IN CONTRAST, THE
00Z CANADIAN ENSEMBLE MEAN HAS A LESS AMPLIFIED SOLUTION WITH RELATIVELY WEAK
ANOMALIES OVER MUCH OF THE CONUS. TODAYS OFFICIAL 500-HPA BLEND CHART INDICATES
ABOVE NORMAL HEIGHTS FOR THE WEST COAST OF THE CONUS, WHILE BELOW NORMAL
HEIGHTS ARE FORECAST FOR THE LOWER MISSISSIPPI VALLEY, THE SOUTHEASTERN STATES,
AND THE OHIO AND TENNESSEE VALLEYS. ENHANCED PROBABILITIES OF ABOVE MEDIAN
PRECIPITATION ARE INDICATED FOR THE LOWER MISSISSIPPI VALLEY, THE SOUTHEAST,
TENNESSEE VALLEY, AND THE MIDDLE ATLANTIC NEAR THE EASTERN TROUGH. WETTER THAN
NORMAL CONDITIONS ARE ALSO PREDICTED FOR PARTS OF THE THE CENTRAL AND SOUTHERN
ROCKIES DUE TO THE MONSOON ACTIVITY. THE FORECAST RIDGE OVER THE WESTERN CONUS
FAVORS DRIER THAN NORMAL CONDITIONS FOR THE WEST COAST. COOLER THAN NORMAL
CONDITIONS ARE FAVORED FOR MUCH OF THE EASTERN CONUS NEAR THE FORECAST TROUGH.
ENHANCED PROBABILITIES FOR ABOVE NORMAL TEMPERATURES ARE INDICATED FOR THE
WESTERN CONUS.
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Quoting Seflhurricane:
DMAX is Approaching TD 2 Lets wait and see what happens later tonight


Dmax is still several hours away.
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Quoting Seflhurricane:
storm chaser looks like a slight shift to the north????


No this is TD2

This is a large shift south.
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Quoting Stormchaser2007:


In simple terms...

Thunderstorms develop at about 2am-3am with disturbances.


Thank You very much!
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Quoting Seflhurricane:
DMAX is Approaching TD 2 Lets wait and see what happens later tonight


DMIN is in about an hour, DMAX is not for another 12 hours
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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.