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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Nice looking out flow associated with TD2, looks like we will have Ana by 11am. Really starting look better and better.
Member Since: Posts: Comments:
3605. WxLogic
Quoting Drakoen:
Just looked over the models dangerous GFS and ECMWF model runs. ECMWF is further south than it's previous run.


Well have to see how ECMWF does at 12Z if it start agreeing with a more W solution which I wouldn't be surprised off since models have been underestimating the A/B High in long range runs.
Member Since: August 14, 2008 Posts: 4 Comments: 4977
Quoting CaneWarning:


I hope the models are wrong. Our local mets all seem very concerned already.


Morning All

The pattern taking shape warrants and extra twist in your cheeks.
Member Since: Posts: Comments:
3603. Drakoen
Don't forget:

000
NOUS42 KWNO 111726
ADMNFD

SENIOR DUTY METEOROLOGIST NWS ADMINISTRATIVE MESSAGE
NWS NCEP CENTRAL OPERATIONS CAMP SPRINGS MD
1714Z TUE AUG 11 2009

NEW NOAA NWS NCEP SUPERCOMPUTER IMPLEMENTATION UPDATE

AS THE FINAL TEST OF THE NEW SUPERCOMPUTERS..NCEP IS PLANNING
TO DISSEMINATE ALL 12Z CYCLE PRODUCTS OPERATIONALLY FROM THE
NEW STRATUS SUPERCOMPUTER IN GAITHERSBURG ON AUGUST 12...IF
THE TEST GOES WELL THEN WE WILL DECLARE STRATUS OPERATIONAL
AT 18Z ON AUGUST 12 AND NCEP PRODUCTION WILL REMAIN ON
STRATUS.

ORIGINALLY..THE ADVERTISED PLAN WAS FOR THE NEW SUPERCOMPUTERS
TO BE DECLARED OPERATIONAL ON AUGUST 18, HOWEVER WITH THE
ANTICIPATED INCREASE IN HURRICANE ACTIVITY IN THE ATLANTIC
NEXT WEEK NCEP NCO HAS DECIDED TO IMPLEMENT THE NEW
SUPERCOMPUTER ON AUGUST 12 IF POSSIBLE IN ORDER TO MINIMIZE
THE EFFECT OF THE TRANSITION ON NWS OPERATIONS.

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.
Member Since: October 28, 2006 Posts: 57 Comments: 30565
Is anyone seeing the spin at 42W 11N near TD2?
Right around the NOAA symbol! LOL!
Member Since: September 30, 2005 Posts: 0 Comments: 1606
3601. cg2916
Quoting nuggsgalore:
Anybody seen the latest CMC? What is that smacking into Texas?



Yeah, I see that.
Member Since: Posts: Comments:
3600. WxLogic
Quoting Stormchaser2007:
12z



Models starting to agreed on a stronger Bermuda High at the end of the period... as you can see by the left turn of the last 1 to 2 points.
Member Since: August 14, 2008 Posts: 4 Comments: 4977
3599. Drakoen
Quoting ackee:
can u show a link to this

Link
Member Since: October 28, 2006 Posts: 57 Comments: 30565
I don't see an exposed center anymore. Looks to be right on the edge of the convection.
Member Since: August 2, 2007 Posts: 19 Comments: 19234
Vorticity slowly but surely increasing.

Member Since: June 9, 2007 Posts: 4 Comments: 15921
Quoting Stormchaser2007:


Thats a time sequence of Andrew.


Be careful using that name...someone yells at me every time I do.
Member Since: April 26, 2009 Posts: 3 Comments: 3667
Quoting AussieStorm:
I hope we don't get this


Thats a time sequence of Andrew.
Member Since: June 9, 2007 Posts: 4 Comments: 15921
Quoting Drakoen:
Just looked over the models dangerous GFS and ECMWF model runs. ECMWF is further south than it's previous run.


I hope the models are wrong. Our local mets all seem very concerned already.
Member Since: April 26, 2009 Posts: 3 Comments: 3667
Anybody seen the latest CMC? What is that smacking into Texas?


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Quoting AussieStorm:
I hope we don't get this
refresh my memory....what the heck is that??!!!
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Quoting claimsadjuster:


Sheri, do you do cat work? And who do you work for? I do and that is why I ask.


Hey, We will get banned talking about this in DrM's blog. So I sent you mail. But we can't really say sent mail. I don't want to get banned. I really like it here. I promise i am not being mean. It's just the rules in here. And some folks will flag you.

Sheri
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Roger that!
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3589. cg2916
Just in case anyone hasn't noticed, the SSD put the Dvorak at T2.5/2.5.
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I hope we don't get this
Member Since: Posts: Comments:
12z

Member Since: June 9, 2007 Posts: 4 Comments: 15921
3586. ackee
Quoting Drakoen:
Just looked over the models dangerous GFS and ECMWF model runs. ECMWF is further south than it's previous run.
can u show a link to this
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New convection going off directly over the center.

We may have Ana at 11

Member Since: June 9, 2007 Posts: 4 Comments: 15921
Greetings...from South Fla
This is an in case you needed to know post...For those following the GFS; I found this.. GFS (National Weather Service Global Forecast System) is the main meteorological model for the United States. The model is run four times a day (six hours apart). It is a merger and expansion of the AVN and MRF models and is extended out to 384 hours.
Member Since: Posts: Comments:
3583. afj3
Hello everyone
I'm a novice at this but is the GFS taking TD2 over South Florida?
Member Since: Posts: Comments:
3582. ackee
the wave of the coast seem to be further north than models been hinting anythoughts
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good morning guys talk to me
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morning everyone...has anyone noticed the canadian model?? WTH is that coming off the yucatan?? is this from that blob in the carrib?
Member Since: Posts: Comments:
3578. IKE
Wave going through the islands is going through 20-30 knots of shear today....looks more favorable in a day or 2....

Member Since: June 9, 2005 Posts: 23 Comments: 37858
Quoting catastropheadjuster:

I really have no ideal. I mainly just lurk and read. There are some very very smart folks on here. I mean there's StormW,Ike,Weather456,Tampaspin,and some others. They will answer your questions. I am still learning myself.

Sheri


Sheri, do you do cat work? And who do you work for? I do and that is why I ask.
Member Since: Posts: Comments:
3576. KEEPEROFTHEGATE (Mod)
Quoting P451:
Can anyone link me to current TCHP images for the Atlantic?

I like the ones that look like this:



I just cannot seem to find any CURRENT ones anywhere.

Thanks in advance.

those TCHP maps are no longer updated till further notice you have to use google earth TCHP maps for current info
Member Since: Posts: Comments:
3575. Drakoen
Just looked over the models dangerous GFS and ECMWF model runs. ECMWF is further south than it's previous run.
Member Since: October 28, 2006 Posts: 57 Comments: 30565
Quoting Adjuster13:


Good Morning Sheri: Whats your opinion on "Where to?"

I really have no ideal. I mainly just lurk and read. There are some very very smart folks on here. I mean there's StormW,Ike,Weather456,Tampaspin,and some others. They will answer your questions. I am still learning myself.

Sheri
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On TD2 you can see the center is still to the east on visible satellite, but the organization and higher cloud tops are now closer to the center.
Member Since: September 30, 2005 Posts: 0 Comments: 1606
3571. IKE
Quoting redwagon:
Ike, that's the same little wave that's been meandering along quietly for about a week now, right?


Yup.
Member Since: June 9, 2005 Posts: 23 Comments: 37858
It wouldn't surprise me if they say - as a compromise - something like: Max winds are near 35mph with higher gusts, but could become a tropical storm at any time.

We'll see.
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The ADT center position seems a bit too far displaced from the convection compared to the other estimates and the 12z estimate.
Member Since: August 2, 2007 Posts: 19 Comments: 19234
3568. ackee
IT WOULD be funny to see all models be wrong about bill affecting LAND forms early head out sea
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3566. KEEPEROFTHEGATE (Mod)

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Quoting AussieStorm:
wind shear is pushing the convection west of the CoC. When they realign there will be more firing of convection


Thank you!
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I think it'll be a close call. Dvorak (and ADT) says it is a TS, the Windsat is picking up 35-40kt barbs on the eastern side and so on. But, the computer guidance still says 30kts and it doesn't have the best outward appearance with the convection displaced a bit.

Wouldn't be surprised either way.
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Quoting catastropheadjuster:
Good Morning everyone. I really hope nothing gets into the GOM. We really don't need that. I mean last year it was detestation in TX. And then before that Katrina,Wilma,Rita and so on.

Sheri


Good Morning Sheri: Whats your opinion on "Where to?"
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Quoting KimberlyB:


Ok. So basically a sunset, sunrise situation then?

I noticed someone mention that they believe the COC has relocated west, into the convection. Does anyone else believe that has or is occurring?
wind shear is pushing the convection west of the CoC. When they realign there will be more firing of convection
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Ike, that's the same little wave that's been meandering along quietly for about a week now, right?
Member Since: Posts: Comments:
Quoting heliluv2trac:
i wonder if weatherstudent is in school


Sleeping probly, he says he doesnt start school till around the 24th. LOL. Now I dont know if thats true or not, just what he said the other day.
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3559. MahFL
Sat pic

Sat pic

When it moves more west use this one.

Closer sat pic

Later I will post more zoomed in pages.
Member Since: June 9, 2004 Posts: 0 Comments: 3550
Quoting hondaguy:
Morning all!

The wave coming off the coast behind TD2 is HUGE. lol


I was just saying that myself. LOL.
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Quoting AussieStorm:

Dmax is night and Dmin is day


Ok. So basically a sunset, sunrise situation then?

I noticed someone mention that they believe the COC has relocated west, into the convection. Does anyone else believe that has or is occurring?
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i wonder if weatherstudent is in school
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About

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