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 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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TD2
Member Since: July 11, 2006 Posts: 14 Comments: 11356
Quoting Chicklit:
guys whats wait in tell 90L gets too 50W then when the storm gets too 50W then will no more where it will end up going
Guys, let's wait until 90L gets to 50W. Then when the storm gets to 50, we'll know more where it will end up going.


OMG this is crazy.....i'm so glad your not my mommy! I would be dead......LOL
Member Since: September 2, 2007 Posts: 178 Comments: 20443
I know Tigger and Orca but it helps me to vent ! empty nester here!! thats why i like the blog being busy lets me stay busy and learn something. Drak even joked the other day so its all good.. lol
Member Since: August 19, 2007 Posts: 0 Comments: 1601

Member Since: July 11, 2006 Posts: 14 Comments: 11356
Quoting RitaEvac:


Looks like Ana is gonna be a B@#%*
To be modern and urban, the @#%* part should be pronounced "eeach".
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Quoting sammywammybamy:
TampaSpin ,

Thats Not Good........is It?


Nope
Member Since: September 2, 2007 Posts: 178 Comments: 20443
Quoting atmoaggie:

The day is long in tooth for answering this in any detail, but here is a discussion that includes a real critique of the methods.
http://blogs.chron.com/sciguy/archives/2009/08/a_hockey_stick_for_hurricane_activity.html
Really, though, it does look a bit far fetched. You think they included only landfalling TC sin the recent numbers? Because those are the only ones that would leave a signal for the distant past.

Thanks! BTW, "Long in the tooth" is one of my favorite sayings!
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Quoting Tazmanian:
we wont no any thing on where the storm is going in tell it gets too 50W forcasting a storm this far out and not noing if where it is going too hit is point less this far out in time

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.
Member Since: July 11, 2006 Posts: 14 Comments: 11356
Quoting tiggeriffic:
remember rare...i got one done with college now!


I have a grandkid already... 8 year old grandson
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Quoting popartpete:
I heard earlier that we are now having more hurricanes than any other time in 1,000 years. I would find dispute with this. Hurricanes were unknown to Europeans until Columbus. The most reliable weather records date back to the mid-1800's and the satellite era has been only since the 60's forward. With GOES, and Quikstat, and others, we can now can see storms forming thousands of miles away, and every expert is watching them continually. Since we can see everything constantly, is there a possibility that we really have not seen a real increase, but just an increase in what we can see? (I have not actually read the report, for full disclosure.) What do the other blog buddies think of this?

The day is long in tooth for answering this in any detail, but here is a discussion that includes a real critique of the methods.
http://blogs.chron.com/sciguy/archives/2009/08/a_hockey_stick_for_hurricane_activity.html
Really, though, it does look a bit far fetched. You think they included only landfalling TCs in the recent numbers? Because those are the only ones that would leave a signal for the distant past.


And a follow-up here: http://blogs.chron.com/sciguy/archives/2009/08/post_108.html
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Quoting popartpete:
Looks like every model has 90L as a 'cane, between a 1 and 3 in 5 days.


Looks like Ana is gonna be a B@#%*
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GFS at 54 hours

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remember rare...i got one done with college now!
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Quoting VAbeachhurricanes:

all models calling for regeneration.


bombed out

Looks like every model has 90L as a 'cane, between a 1 and 3 in 5 days.
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Quoting tiggeriffic:
ok...im out...work early in the morning...will check in tomorrow sometime...nite all and play nice...the cane God's are watching and will drop an eye on you if you don't! LOL


Oh I like that one... the evil eye.. sort of.
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ok...im out...work early in the morning...will check in tomorrow sometime...nite all and play nice...the cane God's are watching and will drop an eye on you if you don't! LOL
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2716. Drakoen
Quoting CaneWarning:
I'm off for bed. I almost wonder if I will wake up to TD3.


Unless you are going to sleep until Friday night at the earliest I don't think so.
Member Since: October 28, 2006 Posts: 57 Comments: 30565
Tigger enjoy it while you can. both of mine are in college now so it goes by fast!
Member Since: August 19, 2007 Posts: 0 Comments: 1601


TD2

90L

AOI
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Quoting Gumbogator:
SST in the Bay of Campeche 92.3 degrees recently and a wicked dew point 262 miles S of Panama City Fla 84.2 yesterday. There is a scary amount of latent heat in all the GOM.


That IS scary, something gotta give sooner or later
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Quoting Chicklit:

Good observation, Greater Antilles.


Oops, thanks for the correction.
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Quoting Chicklit:
Kman, don't you agree that TD2 got rid of a lot of moisture making cyclogenesis more conducive for 90L? Also, SAL is low in front of 90L last I checked and if shear stays in check SSTs should begin to warm, making it easy for a remnant low to regenerate.
Yeah, Clicklit, (BTW, that's the name of a fave character of mine from John Water's 'Female Trouble') what you said is also what Joe Bastardi was saying on Tuesday.
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2710. szqrn1
I'm bugging out.. nite... y'all don't stay up too late ..and be nice..

Looking forward to everyone's insight on your blogs tomorrow!!
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I'm off for bed. I almost wonder if I will wake up to TD3.
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guys whats wait in tell 90L gets too 50W then when the storm gets too 50W then will no more where it will end up going
Guys, let's wait until 90L gets to 50W. Then when the storm gets to 50, we'll know more where it will end up going.
Member Since: July 11, 2006 Posts: 14 Comments: 11356
Charleston County Sammy...can't wait either... will be the first time i have been away from him for more than 2 hours since I got pregnant with him...he goes to both jobs with me...
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nite Kman sleep well and thanks for the great info and for keeping Tampa in check, lol
Member Since: August 19, 2007 Posts: 0 Comments: 1601

all models calling for regeneration.


bombed out

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Quoting sammywammybamy:
Bahamas Blob " SWB Invest"



SWB Invest - In My terms it Should bear Watching


Man, take 9 hours off to go to work, and this thing is here when I get home :)

Is this that AOI that was North of the other AOI as they split up approaching the Les. Ant last week? Have any models acknowledged it yet?
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SST in the Bay of Campeche 92.3 degrees recently and a wicked dew point 262 miles S of Panama City Fla 84.2 yesterday. There is a scary amount of latent heat in all the GOM.
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2701. KEEPEROFTHEGATE (Mod)
2696 good tigger thats good
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Quoting szqrn1:


Hmm.... I never watch the local news..Thanks!
no problem...
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OLD TD2


Invest 90L....the big high is in control..

Member Since: September 2, 2007 Posts: 178 Comments: 20443
Time to turn in for tonight so have a good evening all and catch you tomorrow.
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LOL keeper...hope to get on a bit this season...have 2 jobs to keep up with so won't be on much until they hit the 50-60w mark...got my gear ready to go tho... :)
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There is an "upper anticyclone" over 90L?"
Shouldn't that word be hyphenated?
Member Since: July 11, 2006 Posts: 14 Comments: 11356
Quoting Funkadelic:


I agree with you but Tonight on the Barometer Bob show, they were discussing how the trough may not come all the way down south as predicted before. StormW and Barometer bob I believe were interested in the GFS from this afternoon. It showed 90L Hitting the lesser antilies, scraping Dominican republic, going into south florida, And last but not least ending up in the gulf of mexico.

They both showed some confidence in that model run, and unfortunately stated that it would also be the most problamatic scenario.


if anything gets into the hot tub known as the gom were in for a bumpy bumpy ride!!
Member Since: August 19, 2007 Posts: 0 Comments: 1601
2692. Patrap
Quoting popartpete:
I heard earlier that we are now having more hurricanes than any other time in 1,000 years. I would find dispute with this. Hurricanes were unknown to Europeans until Columbus. The most reliable weather records date back to the mid-1800's and the satellite era has been only since the 60's forward. With GOES, and Quikstat, and others, we can now can see storms forming thousands of miles away, and every expert is watching them continually. Since we can see everything constantly, is there a possibility that we really have not seen a real increase, but just an increase in what we can see? (I have not actually read the report, for full disclosure.) What do the other blog buddies think of this?


Well,core sample from around the BAsin,NOLA,S Carolina and FLorida all show layers of Peat within the ground where one can easily see the Layers that form when Large Hurricanes Knock Down the Tree's and the peat forms a distinct layer.
Kinda Like a tree Ring. I posted a article today on that very question. In New Orleans while the COE were doing the study on the 17th St Canal failure,they found a Large Hurricane struck approx 400 Years ago in a 16 fts sample..that coincides with Indian Lore and History passed down.

So yes we can see where storms formed and how strong they were with a certain degree of accuracy.
Member Since: July 3, 2005 Posts: 426 Comments: 128764
Quoting CaneWarning:


It was a joke Taz! :)



oh ok
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2690. szqrn1
Quoting KATRINABILOXIGIRL:
yes he did


Hmm.... I never watch the local news..Thanks!
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Local met said system near Hispanola has no chance of developing into anything as shear is tearing it up.
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Quoting tiggeriffic:
ok...puter actin up...half the time when i refresh it says no blog entries and i gotta start over...guess someone is tellin me to go to bed cuz i gotta be at work at 7am...then to the school so peewee can meet his teacher... yeah....school starts tuesday...he is goin to KINDERGARDEN!


Thats not your putter... thats the blog servers, been doing that a lot lately
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2687. KEEPEROFTHEGATE (Mod)
Quoting tiggeriffic:
ok...puter actin up...half the time when i refresh it says no blog entries and i gotta start over...guess someone is tellin me to go to bed cuz i gotta be at work at 7am...then to the school so peewee can meet his teacher... yeah....school starts tuesday...he is goin to KINDERGARDEN!
thats good just in time they will all be going back that should quiet the blogs down
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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.