Ana and TD 3 take aim at the Lesser Antilles

By: Dr. Jeff Masters , 4:17 PM GMT on August 15, 2009

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Tropical Storm Ana was born this morning, when the remnants of Tropical Depression Two made a comeback and organized into the first tropical storm of the 2009 Atlantic hurricane season. Ana is the latest first named storm of the season since Hurricane Andrew got its name on August 17, 1992. The two storms have some similarities, as Andrew formed in the same part of the ocean, and also struggled in its early days with high wind shear and dry air. Let's hope the similarities end there.

Ana is struggling this afternoon. After an modest burst of heavy thunderstorm activity prompted NHC to upgrade Ana to a tropical storm early this morning, Ana has run into strong upper-level winds from the west that are creating high wind shear. This shear was not forecast, and it is not clear how long it will last. The shear has acted to drive dry air into the core of Ana, destroying almost all of Ana's heavy thunderstorms. The low-level center of the storm is now exposed to view, something that often foreshadows the death of a storm. It is possible the shear will destroy Ana, and several models (the GFS and ECMWF) forecast this may be the case. However, the shear forecast calls for shear to drop into the low range, 5 - 10 knots, tonight through Tuesday. If the shear does drop as forecast, Ana should be able to moisten the atmosphere around it sufficiently to protest itself from the dry Saharan air that surrounds it (Figure 1). SSTs are 27°C today, and will increase to 28°C by Sunday. By the time Ana moves into the Bahamas, total ocean heat content rises steeply (Figure 2), and rapid intensification of Ana is possible, if the shear and dry air haven't disrupted the storm. The intensity forecast models, for the most part, predict a steady intensification of Ana to the threshold of hurricane strength five days from now. The HWRF model is on the strong side, predicting a Category 2 hurricane. The GFDL predicts a weak tropical storm five days from now, but that is because the model has Ana passing over the rugged terrain of Hispaniola, something the other models do not predict. In summary, the intensity forecast for Ana has higher than usual uncertainty, and I give equal chances that the storm will be a hurricane--or non-existent--four days from now.


Figure 1. Water vapor image from this morning showing the large area of dry, Saharan air surrounding Ana, and lying to the north of Tropical Depression Three. Image credit: NOAA/SSD

Tropical Depression Three forms, could be Bill later today
QuikSCAT data from this morning and satellite loops revealed that the tropical wave (90L) in the middle Atlantic has finally developed a well developed surface circulation and can be classified as Tropical Depression Three. Recent satellite imagery suggests that TD 3 may already be Tropical Storm Bill. Water vapor imagery (Figure 1) shows that TD 3's center consolidated a few hundred miles south of the dry air of the Saharan Air Layer (SAL). Thus, the storm should not be affected by dry air and dust as much as Ana has been. Ana may also act to moisten the atmosphere in front of TD 3, helping protect the storm from the SAL as it edges farther north over the the three days.



Figure 2. Heat content of the ocean, in kJ per square cm. Oceanic heat content steadily increases for Ana and TD 3 as they approach the Lesser Antilles Islands. Oceanic heat content levels of 90 kJ per square cm are frequently associated with rapid intensification of hurricanes. Image credit: University of Miami.

Wind shear is moderate, 15 knots, but is forecast to fall to 10 - 15 knots on days 2 - 5. Sea Surface Temperatures are about 27.5°C, and will remain in the 27.5 - 28°C range the next five days. The combination of low wind shear and sufficiently warm SSTs should allow TD 3 to intensify steadily, and I expect the storm will be at hurricane strength by Wednesday, when it will be near the northern Lesser Antilles Islands. Most of our reliable intensity models strengthen TD 3 into a hurricane by Wednesday. Oceanic heat content (Figure 2) increases sharply just before the islands, so TD 3 could be intensifying rapidly as it moves through or just north of the Lesser Antilles on Thursday. TD 3 consolidated farther south than expected, so the track models calling for a more northerly path were probably incorrect. In particular, the ECMWF model, which had TD 3 turning sharply northwestward and missing the Lesser Antilles Islands, was probably much too far to the north in this morning's 00Z run. TD 3 will probably pass very close to the northern Lesser Antilles islands on Wednesday and Thursday.

I'll have an update Sunday.

Jeff Masters

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3114. Patrap
GOM 60 Hour Water Surface Temperature Forecast Model
Member Since: July 3, 2005 Posts: 419 Comments: 127358
that avatar is just killin' me...Goober Beefcake...
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3112. kachina
Quoting Stormchaser2007:
Hm. interesting.




91L looks pretty nasty to me. Are the water temps and wind favorable for development?
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Quoting hurricane23:
2 weak systems and a fish :(


LOL

Cmon man.

We finally have something to track.
Member Since: Posts: Comments:
Just mid-levels mike nothing at the surface.Should be inland soon
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Quoting DM21Altestic:

Quoting DM21Altestic:



THATS funny
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Quoting WeatherStudent:


I gotcha, KMan. Geeze, G'nite.


PS

You really do need a new Avatar, IMO of course !!
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3107. code1
Is it possible to gain a bit more of young and old testosterone in here? sheesh
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Quoting Patrap:
Guess who seeing a Ana, Bill double whammy GFS 00run over his house..



Best, funniest, ugliest post all night ROFLMAO!!!!
Member Since: September 3, 2007 Posts: 3 Comments: 1519
Here is the first model runs...HUM it has time to strengthen on that track.

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Hm. interesting.


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Quoting FloridaTigers:


In front of a cute, pretty shower curtain

Careful, she might scratch your eyes out...
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3100. Patrap
Quoting HaboobsRsweet:
Hey Patrap... I havent paid attention to the invest in the Gulf until about 5 minutes ago. Is it going to just be a rain producer for us or do you thinkw e actually get a classification out of it?


I think its going to be close call on TS strength,but not out the realm of Possibility.

GOM Loop Current and Eddy's 60 Hour Model
Member Since: July 3, 2005 Posts: 419 Comments: 127358
Quoting Stormchaser2007:


ROFL!!!

I have been lurking for a while but this really made me laugh.


Ok, you guys forced me to look at what your talking about... not nice.. not nice at all.. that picture is just not right
Member Since: Posts: Comments:
Quoting TampaSpin:
The wind has picked up to a very steady breeze!



The University of Tampa, Tampa, Florida (PWS)
Updated: 1 sec ago
77.5 °F
Clear
Humidity: 91%
Dew Point: 75 °F
Wind: 13.0 mphfrom the ESE
Wind Gust: 22.0 mph


Member Since: April 26, 2009 Posts: 3 Comments: 3667
rain bands building in the GOM and moving ashore here on seista key in sarasota,I would not be suprised if we have TD4 in the GOM and the first hurricane of the season,bill in the 5am ...
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Quoting homegirl:


91L is deepening. Radar shows nice LLC and even possible banding features. Not much time for strengthening, obviously...but I'm calling TD04 by 5am.


looks pretty tdish to me... just need to get it up to 30mph winds



Loop
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Quoting hurricane23:
2 weak systems and a fish :(


Tracks can change, I wouldn't call it a fish storm right away.
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Quoting KATRINABILOXIGIRL:
correct me if I'm wrong but did I read previously that you are a Freshman in HIGH SCHOOL? let me give you a heads up then...when you have a family and a home and things that you have worked for all of your life and you go through somehting as devastating as these can be and you lose them including possibly your life then you may think twice about saying something as stupid as that

You are dead right...when i was in high school i was so excited for storms to hit my area. I loved it. Now that I own a house 2 cars and a bunch of crap in the house, I dont want a storm to even think about coming near by plus here in Biloxi they have finally started making progress on rebuilding so we dont need another one right now.
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Quoting WeatherStudent:



Continue to bother me and I will notify the blog admin. I hope I just made myself clear.
Come on JFV you have been permenetly ban once so if ya can't take the heet,leave the kitchen LOL
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Quoting Funkadelic:


You thinks that's possible? In my opinion that would be hard for Mr. Bill to pull off..

Possible yes. Rare, yes. Is Bill the one to do it? I have doubts. More likely if he were a small cat 1 not a big-windfield kinda guy.
Member Since: August 16, 2007 Posts: 6 Comments: 12461
Tropical Storm Ana, Tropical Storm Bill, and Invest 91L Analysis

Ok, instead of putting 3 separate bulletins together, I found a way to do the map with all 3 storms. Soo.. Lets get going

Starting with...

Tropical Storm Bill
Heavy thunderstorms are beginning to reform with the storm, it was named Bill at 5 p.m. The track is beginning to become a bit clear. I doubt and have always doubted that it would reach the Gulf of Mexico. My "gut feeling" is still possible where it heads up the East Coast and strikes Long Island, not that I wish it on them, but this is the way the pattern is set up. Bill has winds of 40 mph., though it seems to be organizing quite well tonight. Might be 50-55 mph. by 5 a.m. tomorrow. The track of Bill is all about timing. If Bill is fast, it will head more west. though if Bill is slow, out to sea he goes. It will become a Hurricane in about 2-3 days, maybe even making major Hurricane status when it gets to the Bahamas. 2 weeks away, we have plenty of time to watch Bill, but please make Hurricane prep plans just in case. I'm checking my generator out next week.

Tropical Storm Ana
Ana formed 5 a.m. this morning from what was a pesky Tropical Depression that was classified earlier a few days ago, then downgraded to a wave, then re-classified 24 hours ago. Tropical Storm watches are up for the northern Leeward Islands. Ana might impact South Florida in 5 days, but also has a good chance of weakening back to a wave due to some dry air entraining into it. This is clearing all the dry air for Bill to strengthen.. It's like Ana is a shield for Bill. I'm not as concerned about TS Ana as I am with TS Bill but I would not be surprised if Ana were to strengthen in a few days due to very warm water temperatures.

Invest 91L
Warm temperatures is what might cause 91L to repeat a similar storm that happened to strengthen to a Hurricane in 24 hours. I am not saying 91L is going to become a Hurricane, but possibly a Tropical Storm before making landfall on the northern Gulf Coast, most likely Louisiana. I don't like the looks of this.. This is really cranking up and I find no reason why it shouldn't. these conditions are more ripe then what Wilma (2005) formed in. Folks on the northern Gulf Coast may be waking up to Tropical Storm Claudette with warnings. I hope that people are cautious on what might just occur tonight..

After those 3 analysis, I made a map concerning possible tracks of those 3 systems. Ana is yellow, Bill is red, and 91L is blue

Photobucket
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2 weak systems and a fish :(
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3086. jipmg
Quoting Funkadelic:


You thinks that's possible? In my opinion that would be hard for Mr. Bill to pull off..


I honestly dont know what that means, a turn 10 degrees or w.e can you elaborate? LOL
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Quoting EldritchWind, thanks for the info, the feel of the air does tell...
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Quoting Drakoen:


LOL! LOL! LOL! @ ur curtains. True Gangster!!!


ROFL!!!

I have been lurking for a while but this really made me laugh.
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3083. Patrap
Guess who seeing a Ana, Bill double whammy GFS 00run over his house..


Member Since: July 3, 2005 Posts: 419 Comments: 127358
Quoting weatherwatcher12:

Not according to the quikscat.

And lost all lower level convergence as soon as sun set happened.

Member Since: August 16, 2007 Posts: 6 Comments: 12461
The wind has picked up to a very steady breeze!

Member Since: Posts: Comments:
Quoting DM21Altestic:

Actually, I do. haha
correct me if I'm wrong but did I read previously that you are a Freshman in HIGH SCHOOL? let me give you a heads up then...when you have a family and a home and things that you have worked for all of your life and you go through somehting as devastating as these can be and you lose them including possibly your life then you may think twice about saying something as stupid as that
Member Since: July 31, 2009 Posts: 0 Comments: 324
I'm out for tonight gang. Wow LOL
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Quoting kachina:


I'm just confused...why would someone be wearing a leather jacket, hat and sunglasses in the bathroom????


In front of a cute, pretty shower curtain
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Quoting WeatherStudent:



Continue to bother me and I will notify the blog admin. I hope I just made myself clear.


You should send those attack fish afer him!
Member Since: April 26, 2009 Posts: 3 Comments: 3667
Hey Patrap... I havent paid attention to the invest in the Gulf until about 5 minutes ago. Is it going to just be a rain producer for us or do you thinkw e actually get a classification out of it?
Member Since: Posts: Comments:


91L is looking better than ANA at this point and will not be surprise since it is heading WNW and slowing down given it even more time to organize that by tomorrow night have Tropical storm warnings somewhere in the GOM.. it is pulling a humberto
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What luck Sarasota has! Been in a drought for years and with 91L right of shore still no rain.
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Quoting kachina:


I'm just confused...why would someone be wearing a leather jacket, hat and sunglasses in the bathroom????


I have an idea but I will not post it here.
Member Since: April 26, 2009 Posts: 3 Comments: 3667
Quoting Drakoen:


LOL! LOL! LOL! @ ur curtains. True Gangster!!!


My sides are hurting LMAO
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3066. kachina
Quoting kmanislander:


Well, the pretty fish send a different message from the black leather. I'm just not going there LOL


I'm just confused...why would someone be wearing a leather jacket, hat and sunglasses in the bathroom????
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3065. KEEPEROFTHEGATE (Mod)
91L RUN

425

WHXX01 KWBC 160102

CHGHUR

TROPICAL CYCLONE GUIDANCE MESSAGE

NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL

0102 UTC SUN AUG 16 2009



DISCLAIMER...NUMERICAL MODELS ARE SUBJECT TO LARGE ERRORS.

PLEASE REFER TO NHC OFFICIAL FORECASTS FOR TROPICAL CYCLONE

AND SUBTROPICAL CYCLONE INFORMATION.



ATLANTIC OBJECTIVE AIDS FOR



DISTURBANCE INVEST (AL912009) 20090816 0000 UTC



...00 HRS... ...12 HRS... ...24 HRS. .. ...36 HRS...

090816 0000 090816 1200 090817 0000 090817 1200



LAT LON LAT LON LAT LON LAT LON

BAMS 25.9N 83.1W 27.2N 85.4W 28.4N 87.2W 29.4N 89.1W

BAMD 25.9N 83.1W 27.1N 85.1W 28.1N 87.0W 29.0N 88.9W

BAMM 25.9N 83.1W 27.1N 85.1W 28.1N 87.0W 29.0N 88.8W

LBAR 25.9N 83.1W 27.3N 85.2W 29.0N 87.3W 30.7N 89.0W

SHIP 25KTS 28KTS 35KTS 40KTS

DSHP 25KTS 28KTS 35KTS 40KTS



...48 HRS... ...72 HRS... ...96 HRS. .. ..120 HRS...

090818 0000 090819 0000 090820 0000 090821 0000



LAT LON LAT LON LAT LON LAT LON

BAMS 30.3N 90.7W 31.9N 93.6W 34.5N 95.6W 37.9N 85.6W

BAMD 30.0N 90.7W 32.3N 93.4W 36.6N 91.0W 41.9N 72.1W

BAMM 29.9N 90.6W 31.6N 93.5W 34.5N 94.9W 39.2N 80.9W

LBAR 32.8N 90.0W 36.4N 87.4W 38.1N 78.1W 34.1N 75.3W

SHIP 49KTS 63KTS 70KTS 76KTS

DSHP 34KTS 28KTS 27KTS 28KTS



...INITIAL CONDITIONS...

LATCUR = 25.9N LONCUR = 83.1W DIRCUR = 300DEG SPDCUR = 14KT

LATM12 = 24.2N LONM12 = 80.2W DIRM12 = 295DEG SPDM12 = 13KT

LATM24 = 23.5N LONM24 = 78.0W

WNDCUR = 25KT RMAXWD = 30NM WNDM12 = 25KT

CENPRS = 1013MB OUTPRS = 1014MB OUTRAD = 125NM SDEPTH = M

RD34NE = 0NM RD34SE = 0NM RD34SW = 0NM RD34NW = 0NM



$$

NNNN
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Quoting flsky:


Go away.


ditto
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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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