TD 2 nearly dead; African disturbance 90L gathering strength
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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What day is this model indicating?
True... with a more pronounce turn after 55W or so... will be interesting to see if the 12Z run of the ECMWF still agrees with the trough strength.
Why do you make some of your posts so hard to read?
LMAO.
Surface
Condition Points
A circulation is evident using visible satellite, shortwave infrared, microwave imagery or QuikSCAT/Windsat ambiguities
3 points
A circulation has been evident for at least 24 hours
5 points
A westerly surface- or gradient-level wind of 5 kt that is within 200 nm (370 km, 230 mi) south of the centre of the disturbance
5 points
Any wind associated with the system is at least 20 kt
2 points
Any wind associated with the system is at least 25 kt
3 points
Any wind associated with the system is at least 30 kt
4 points
A weather station within 200 nm of the system has reported had a pressure drop of 2 mb over 24 hours
3 points
A weather station within 200 nm of the system has had a pressure drop of 3 mb over 24 hours
4 points
The estimated MSLP of the system is less than 1010 to 1009 mb
3 points
The estimated MSLP of the system is 1008 mb or less
4 points
[edit] 500 mb height
Condition Points
There is evidence of at least an inverted trough
2 points
There is evidence of a closed circulation in the system
4 points
[edit] 200 mb height
Condition Points
Westerly flow of at least 15 kt over the disturbance
-4 points
There is evidence of anticyclonic outflow over the centre of the disturbance
4 points
Easterly flow of at most 20 kt over the disturbance
3 points
[edit] Sea surface temperature
Condition Points
The sea surface temperature is 26 Celsius (78.8 Fahrenheit) or higher
3 points
[edit] Satellite data
Condition Points
The system has persisted for at least 24 hours
3 points
The system has persisted for at least 48 hours
4 points
The system has persisted for at least 72 hours
5 points
The system has a Dvorak classification of T1.0 to T1.5 from all three agencies (TAFB, SAB, AFWA)
3 points
The system has a Dvorak classification of T1.5 to T2.0 from all three agencies
5 points
The Dvorak final-T number has decreased by T0.5 to T1.0 from two or more agencies
-2 points
[edit] Miscellaneous
Condition Points
The cloud system is north (or south) of 5 degrees latitude
3 points
The tropical system is within 72 hours of reaching a Department of Defense resource
3 points
The cloud system center and the satellite centre fixes for the system are within 2 degrees of each other
2 points
Bonnie and Charley?
Thanks. I guess I'll just trust the storms, ikes, and draks.
Had to come out of lurking mode for this. People realize this, they're just not panicking. This isn't even a storm yet. Use common sense, analyze it, pay attention to it, but it's way too early to post nothing but doom and gloom because of a gut feeling.
Thank you for the Kind words and for your continued support.
Patrick
LMAO!!
Yea good thing thats a long way out - we don't need a hurricane
LOL... quite true IKE. To me is more like a training exercise to be able to get a general feel about the trends. :)
Around 279-300 hours.. not accurate, but this has been a possible trend. It will definitely impact the Lesser Antilles in some way, if it were to recurve it can't recurve until after it passes south of Bermuda. So ALL of the East Coast needs to closely monitor the progress of 90L. Would not surprise me to see a code red by 2 p.m. with how it's been organizing. Just needs deep convection which should happen tonight.
clever :)
Have been seeing a few allusions around here by local mets that they are starting to watch the GOM a little. I'm thinking nothing to worry about except maybe a potential heavy rain maker... any thoughts? I get that the lingering trof could pose some development, but is there really enough time for anything to happen out there outside of maybe a TD3 at best?
If that did happen, Joe Bastardi would have a field day gloating about his forecasts.
what link shows pressure "dropping like a rock"?...and organization still has a ways to go...and models to florida are long range 12 days+ which should not be taken for pure fact (its gonna happen)...
Say what????
T... H.... E..... Type it slowly. THE is spelled THE. Im sorry. I have watched you spell the TEH for many many days now. I just couldnt help myself.
It looks like it would eat the islands, then PR, then Haiti.
Are you typing with your eye's closed or did you just wake up?
Press - Portlight Response Plan looks very good. I will give it a bit more thought, but I can not think of anything that I would suggest to add to the plan.
This loop is sort of fun. Shows the SAL attempting to hem in TD2, and shows TD2 throwing it back off.
for Les,Play on in the Big Gig in the Sky bro,..
8-14 day prognostic discussion talks about a strong trough in the east. Based on where 90L is at now, it's doubtful it reaches the gulf coast if that time period verifies. That's over 4 thousand miles it has to travel in say 11 days. It better be moving 15-20 mph.
Odds are, for now....islands...beyond that is a ?.
If I had to guess...curves east of USA coast.
Florida public education at work...
What is Duffy's? We don't have one in Tampa.
He would be jumping up and down in his cage
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