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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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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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!


It's not your computer--it's the site. So many people are commenting/viewing that it's causing the server to overload with too many connections and what-not. Just refresh--it goes away.
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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
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Quoting hurristat:
I leave for 12 hours, and you guys drop 1800 posts on me. How in the world am I supposed to read back and read all the posts?

Live in the past or jump into the present. But check out Post # 2561. Watch the video and look at 90L.
Holy Cow Batman!
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Quoting Tazmanian:



????



It was a joke Taz! :)
Member Since: April 26, 2009 Posts: 3 Comments: 3667
2682. szqrn1
Quoting TampaSpin:


Susan this is the main site. I use Eumetsat for Africa.

Emuetsat link


Thanks! :) Remember I don't quite get all the highly technical stuff... but I DO get the pretty pictures!
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Quoting TampaSpin:


Susan this is the main site. I use Eumetsat for Africa.

Emuetsat link



EUMETSAT is now available on Google Earth, and its updated every 15 minutes

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Quoting szqrn1:


Hey I am just North of Long Beach.... Mike Reader said we will get this?
yes he did
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2678. KEEPEROFTHEGATE (Mod)
Quoting tiggeriffic:
hiya keeper...still bouncin...so...when did they open the gates and let ya out this time... he he he
gate open jun1 close up nov 30

lol
long stretch
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Quoting CaneWarning:


You're supposed to read the ALL before posting.



????

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Quoting Drakoen:
Another look at the models which are tightly clustered:


Must say that I'm very impressed with the consensus, but as we know, this could change.
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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!
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2673. Patrap
Quoting KEEPEROFTHEGATE:
sorry pat i know i don't like it myself but thats the stark reality friend but as you would say all one really needs to do is prepare get a plan


Yes,Indeed..always.

Calamity will find someone...unfortunately
Member Since: July 3, 2005 Posts: 426 Comments: 128668
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?
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Quoting hurristat:
I leave for 12 hours, and you guys drop 1800 posts on me. How in the world am I supposed to read back and read all the posts?


You're supposed to read them ALL before posting.
Member Since: April 26, 2009 Posts: 3 Comments: 3667
Quoting hurristat:
I leave for 12 hours, and you guys drop 1800 posts on me. How in the world am I supposed to read back and read all the posts?


If you expect to read all the comments here, don't leave for 12 hours. :p
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2669. szqrn1
Quoting KATRINABILOXIGIRL:
local weather just said should be starting to get some of that wave here late Saturday and last thru Tuesday...looks like I better get out the rubber shoes to be delivering the mail..yuck


Hey I am just North of Long Beach.... Mike Reader said we will get this?
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Quoting szqrn1:


I am always looking at this too..can you get this though in a more eastern view so you can see what just comes off africa?


Susan this is the main site. I use Eumetsat for Africa.

Emuetsat link
Member Since: September 2, 2007 Posts: 178 Comments: 20443
dang thanks orca...hope beachfoxx is doing ok...i'm sure surfmom is getting her board ready....
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Local weather keeps saying watch this one over the next week. Tune in each time the news is on. They also end it with some ominous line such as "this could play a part in our weather in a week and a half".
Member Since: April 26, 2009 Posts: 3 Comments: 3667
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
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I hate this time of year
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Quoting TampaSpin:


Yes the blob in the Bahamas could be a stinker when it gets in the GOM which it does appear to be heading about Sunday.
local weather just said should be starting to get some of that wave here late Saturday and last thru Tuesday...looks like I better get out the rubber shoes to be delivering the mail..yuck
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Quoting Nolehead:
2626. Orcasystems 3:24 AM GMT on August 14, 2009
Quoting rareaire:
howdy tigger! Seems like old home week on here except I dont remember Orca's halo being that shiny!!


Its a new one... BeachFoxx and Surfmom got it for me at Christmas :)


haven't seen foxx or mom in here in a while....


BeachFoxx is recovering from a Car accident, and Surfmom has been around on and off.. trust me, they are still here.. they pick on me in my blog all the time :(
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Quoting jasoniscoolman10:
Tropical Depression 2 was located near 14.0N 36.9N, moving off towards the west near 12 mph. Estimated surface winds are near 30 knots with a minimum central pressure of 1007 mb. Anyone with two eyes can see this depression has weakened considerably over the past 24 hrs. Shortwave infrared imagery showed the expose low-level circulation with little associated convection. This system has been undergoing 15-20 knots of easterly shear and guess where it is originating. The easterly shear that is affecting TD 2 is coming from the upper anticyclone over 90L. Interesting stuff. Tropical Depression 2 may eventually escape the clutches of 90L over the next 48 hrs and still has a chance to make it to tropical storm strength.

The weakening of TD 2 has not surprisingly led to a more southerly track. If you remember from my update yesterday and Tuesday, I pointed out the difference between the shallow and deep layer flows. This system will still feel the weakness and pull north but may still entirely miss it. I think the Northern Leeward Islands should monitor the progress of TD 2 based on the trend; as if we don’t have enough on our minds already.



Sounds very much like StormW's update.
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2660. Patrap
Member Since: July 3, 2005 Posts: 426 Comments: 128668
I leave for 12 hours, and you guys drop 1800 posts on me. How in the world am I supposed to read back and read all the posts?
Member Since: October 15, 2008 Posts: 11 Comments: 2312
2658. JLPR
Quoting Drakoen:
Another look at the models which are tightly clustered:


yikes not good =\
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Quoting weatherblog:


Doesn't look too good for the Leewards and Puerto Rico.

Good observation, Greater Antilles.
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This is fairly recent...shows some pretty intense banding on the north side.

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hiya keeper...still bouncin...so...when did they open the gates and let ya out this time... he he he
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2653. KEEPEROFTHEGATE (Mod)
Quoting Patrap:
I really Hate that Map KOTG every time I see it,and the Calender
sorry pat i know i don't like it myself but thats the stark reality friend but as you would say all one really needs to do is prepare get a plan
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Quoting Drakoen:
Another look at the models which are tightly clustered:


The models are in very good agreement. Now the question is do they have a clue as to what they are projecting. I'd sure be nervous if I lived in the islands.
Member Since: April 26, 2009 Posts: 3 Comments: 3667
Quoting Orcasystems:


New Google Graphic
EUMETSAT Real time imagery that updates every 15 minutes.

Look at the next blob coming off Africa..


That blob has been developed by this model
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2650. Patrap
Former TD 2 is a Puff and a sneeze compared to the Frays behind it..as its no Longer nuthing.

Member Since: July 3, 2005 Posts: 426 Comments: 128668
Quoting Patrap:
If 90L can be all she can in a weeks time, TD 2 will be a Faded memory Lost to well,.Calamity downstream after

In 2 days time TD2 will be dead imo.
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2648. hydrus
Quoting tiggeriffic:
it isn't fair...everytime a storm is headed toward PR...my ex is on the west coast of the usa...
lol...
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2626. Orcasystems 3:24 AM GMT on August 14, 2009
Quoting rareaire:
howdy tigger! Seems like old home week on here except I dont remember Orca's halo being that shiny!!


Its a new one... BeachFoxx and Surfmom got it for me at Christmas :)


haven't seen foxx or mom in here in a while....
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Quoting kingzfan104:
so that would mean a track more towards se fla?


Not quite, it could either go out to sea passing just east of the East Coast, kind of like Edouard in 1996. It could track up the East Coast and hit the Northeast, or it could maybe get into the eastern GOM and hit the Panhandle, or the east coast of Florida like Frances in 2004. It's still near Africa and we really can't even be sure of what area if will be in. Just wait and see what happens in the next 5 days. Once it gets to the Islands, we might have an idea of what area it will go to, not the exact landfall if any.
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Drak, we were refering to the ensembles, not your image of the dynamics... check out the ensembles and how consistent they are even out to 96 hours.
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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.


90L is a massive system in a moist environment much further South than TD2 started out at. As such, it has a much better chance of organizing, both from an atmospheric moisture content perspective but also the SST from being further S.

If you look at the WV image ahead of the remnant low of TD2 it is extremely dry from 44 W onwards. Frankly, I do not think TD2 will return. It has also started moving N of due W which will take it into increasingly marginal SST.

My prognosis is no regeneration.
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Quoting Nolehead:
tampaspin...this might be one of those sneaker storm ....just might catch everyone off guard that don't normaly watch these things....


Yes the blob in the Bahamas could be a stinker when it gets in the GOM which it does appear to be heading about Sunday.
Member Since: September 2, 2007 Posts: 178 Comments: 20443
2641. szqrn1
Quoting TampaSpin:
For those that would like a great look at the Tropics this is a great look that i use all the time.


I am always looking at this too..can you get this though in a more eastern view so you can see what just comes off africa?
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Quoting Drakoen:
Once this thing gets going its really going to get going.


I noticed the GFDL and HWRF bring this up in strength rather quickly, even this far out east.
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2639. KEEPEROFTHEGATE (Mod)
Quoting tiggeriffic:
lol rare...look real close and you can see the horns holding up that halo!
lol

hello tigger still bouncing around
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2638. Patrap
I really Hate that Map KOTG every time I see it,and the Calender
Member Since: July 3, 2005 Posts: 426 Comments: 128668
Quoting Orcasystems:


Its a new one... BeachFoxx and Surfmom got it for me at Christmas :)


now thats funny!
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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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