TD 2 nearly dead; African disturbance 90L gathering strength

By: Dr. Jeff Masters , 2:38 PM GMT on August 13, 2009

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Tropical Depression Two is near death, but is still worth watching. The dry, Saharan air to the north and west of the depression, combined with moderately high levels of wind shear of 15 - 20 knots, have almost completely destroyed all of TD 2's heavy thunderstorms. Satellite loops of the storm show a well-formed circulation, but almost no heavy thunderstorm activity.

Wind shear over TD 2 is expected to remain in the modereate range, 10 - 20 knots, over the next five days. Sea Surface Temperatures (SSTs) are 27°C, but will warm to 28°C three days from now. There is plenty of dry, stable air from the Saharan Air Layer (SAL) to to TD 2's north and west that will continue to cause the storm problems. The relatively cool SSTs and dry air mean that TD 2 will not be able to intensify quickly, and some of the models indicate the TD 2 may get destroyed in the next day or two. However, several models still predict TD 2 will become a tropical storm. The HWRF model predicts TD 2 will become a hurricane five days from now, but this seems unlikely given the dry air and relatively high wind shear affecting the storm.


Figure 1. Tropical Depression Two (left side of image) and tropical wave 90L (right side of image).

African tropical wave 90L
A strong tropical wave with a large circulation and plenty of heavy thunderstorm activity is a few hundred miles south of the Cape Verdes Islands, off the coast of Africa. NHC dubbed this disturbance 90L this morning. This morning's QuikSCAT pass shows that 90L has a very large circulation, and top winds of about 30 mph. Satellite imagery from the European METEOSAT satellite show that the heavy thunderstorms associated with 90L are in two major bands, to the north and to the south of the center. There is no heavy thunderstorm activity near the center yet, and this would have to happen before 90L can be named Tropical Depression Three. Water vapor imagery shows that since 90L is forming several hundred miles south of the dry air of the Saharan Air Layer (SAL), the storm should not be affected by dry air and dust as much as Tropical Depression Two has been. Wind shear is about 20 knots over 90L, and is forecast to remain in the moderate range, 10 - 20 knots, over the next five days. Sea Surface Temperatures are about 28°C, and will remain in the 27 - 28°C range the next five days, which are high enough above the 26°C threshold for tropical cyclone formation to allow some slow development to occur. The GFS and ECMWF models continue to predict the development of this wave, though they are now less aggressive about intensifying it than they were in earlier runs. The consensus among the reliable HWRF, GFDL, GFS, and ECMWF models is to bring 90L to point near or just north of the northernmost Lesser Antilles Islands 6 - 8 days from now. The storm could be at hurricane strength by then, as forecast by the SHIPS intensity model.

I'll have an update Friday morning.

Jeff Masters

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Quoting willdunc79:
Ok again been off line since early this morning so how is 90L looking & doing tonight?


Not very organized.....Needs probably a day or 2 before becoming a TD or Storm.
Member Since: September 2, 2007 Posts: 178 Comments: 20443
Thanks so much extreme I thought I was going to be ignored asking about weather on a (suppose to be) weather blog secretly disguised as a English blog.
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No real center yet.

Goodnight fellow Wunderbloggers.
Prayers for the people of China.
CopingMarakotLink
Member Since: July 11, 2006 Posts: 14 Comments: 11351
2784. sctonya
Quoting willdunc79:
Ok again been off line since early this morning so how is 90L looking & doing tonight?


SSDD...Same $&*# Different Day....Still a guessing game.
**Not trying to be a smarty-pants, but that just about covers it. And I noticed that nobody else answered you**
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Quoting Tazmanian:



lol


The little depression that could?
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Quoting willdunc79:
Ok again been off line since early this morning so how is 90L looking & doing tonight?


Increasing convection, computer models developing it into a category 3 hurricane, and marginal conditions ahead (right?) of it, so.. it's an all-go for this storm. :p
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Quoting willdunc79:
Ok again been off line since early this morning so how is 90L looking & doing tonight?
starting to come together. Still rather broad. will probably take another 24-36 hours to tighten up and become td3 or TS Ana.
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2780. JLPR
Quoting Chicklit:
TD2 still has spin.
Link


yep it does
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2779. palmpt
It is going to be tiring next few days!
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Quoting willdunc79:
Ok again been off line since early this morning so how is 90L looking & doing tonight?


More impressive than earlier I should say.
Member Since: August 2, 2007 Posts: 19 Comments: 19234
Quoting hunkerdown:
that would reinforce its death


true, but it also implies regeneration.... AND ZOMBIES... OMGWEREALLDEAD

lol
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Quoting Chicklit:
TD2 still has spin.
Link



lol
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2775. Patrap
Member Since: July 3, 2005 Posts: 426 Comments: 128667
is this a school blog now on how to spell??



can we get back too 90L
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Ok again been off line since early this morning so how is 90L looking & doing tonight?
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TD2 still has spin.
Link
Member Since: July 11, 2006 Posts: 14 Comments: 11351
Quoting hurristat:


I wonder if TD2 will start doing the thriller dance...
that would reinforce its death
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Quoting rareaire:
Tampa sorry to have to do this but its "ignore"


OH that's it buddy....Im's don wis yu......LOL
Member Since: September 2, 2007 Posts: 178 Comments: 20443
2768. JLPR
Quoting rareaire:
jlpr hows that storm to your south feeling it yet?


what storm? xD
tonight is clear =]
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Quoting druseljic:


In the tropics sometimes the ones we call "dead" have a hard time accepting that and try to come back to life, lol!


I wonder if TD2 will start doing the thriller dance...
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Tampa sorry to have to do this but its "ignore"
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Quoting sammywammybamy:


Are You in The Feild of English/ Grammer?

Just Asking..


And its

(Sammy-Wamm-y-Bamm-y)

And I Hate my Name..

I Made 5 years ago...

I Wish it Could Be:

Hurricane Tracker SFLA
you are probably about to get bashed, you spelled "field" wrong.
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Quoting hurricane556:


http://weather.msfc.nasa.gov/cgi-bin/post-goes


That won't work. Use this link instead:
Link
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jlpr hows that storm to your south feeling it yet?
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Quoting Chicklit:
That is not "mean" SamWhamBam.
I am a professional language artist, among other things. Have studied linguistics, create learning plans in intricate detail on language. Read Middle English.
It is language period.
Not doing a dissertation here.
But not mean-intended at all.


I have a Bachelor's Degree in 4 areas of study....one is a professional ignor user button pusher if this editing stuff does not stop.......
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Quoting hunkerdown:
more like professional bs artist

Yes, that too. (deleted the "among other things.")
ROFL!
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Quoting TexasHurricane:


Got a link for that?


http://weather.msfc.nasa.gov/cgi-bin/post-goes
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2759. JLPR
TD 2 convection is being blown to the west it is trying to comeback but the shear wont let it
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Quoting hurricane556:
former td 2 looks like it might be trying to make a comeback


Got a link for that?
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.
Member Since: August 3, 2008 Posts: 16 Comments: 5885
Quoting jasoniscoolman10:


If that continues to keep going, TD3 by morning. DMAX hasn't even arrived over there yet, a few more hours to go.
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Quoting rareaire:
ok Tampa Spin td2 refires goes over Kmans house and into your neighborhood! feel good about that one? worked hard on that synopsis and im not waiting till it gets to chicklits coordinates to decide..


To freaking funny......YOU IS DA MAN!....I'm sure Chicklit will corrects me's gram'a...LOL
Member Since: September 2, 2007 Posts: 178 Comments: 20443
Quoting Chicklit:
That is not "mean" SamWhamBam.
I am a professional language artist.


HAHAHAH LOL
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Drak...post 2258 is an amazing image. Where can I find that?
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Quoting hurricane556:
convection on the increase with former td 2


Deep convection is spotty, not well organized, and has been sputtering ever since even prior to its declaration as a remnant low.
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2750. 7544
question not saying it will happen but scince katrina if a cat 5 or higher was a threat to any land area have they extended the time frame to give warnings or will it still be 3 or 5 days out before they warn the public tia
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Quoting TampaSpin:


Your not allowed to say that on here.....remember it is dead....LOL...yes you are correct...


In the tropics sometimes the ones we call "dead" have a hard time accepting that and try to come back to life, lol!
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first time I've been able to log on since about 10am this morning so how is 90L looking right now?
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ok Tampa Spin td2 refires goes over Kmans house and into your neighborhood! feel good about that one? worked hard on that synopsis and im not waiting till it gets to chicklits coordinates to decide..
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Quoting hurricane556:
convection on the increase with former td 2


Your not allowed to say that on here.....remember it is dead....LOL...yes you are correct...
Member Since: September 2, 2007 Posts: 178 Comments: 20443
Quoting Chicklit:

TD2
that would be former, or ex td2, now a remnant low.
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former td 2 looks like it might be trying to make a comeback
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That is not "mean" SamWhamBam.
I am a professional language artist.
Have studied linguistics.
Create student learning plans in detail.
Read Middle English.
It is language period.
Not doing a dissertation here.
But not mean-spirited whatsoever.
Member Since: July 11, 2006 Posts: 14 Comments: 11351
convection on the increase with former td 2
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Quoting Chicklit:

We won't know anything about where the storm is going until it gets to 50W.
Forecasting a storm this far out and not knowing where it is going to hit is pointless this far out in time.
what point are you trying to prove, we know what Taz is saying. Give it a rest, please.
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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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