Tropical Storm ALETTA

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TROPICAL STORM ALETTA DISCUSSION NUMBER  11
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   EP012006
200 PM PDT MON MAY 29 2006

THE LOW-LEVEL CENTER OF ALETTA BRIEFLY APPEARED EARLIER TODAY AS A
BANDING FEATURE WAS TRYING TO DEVELOP EAST OF THE CENTER. HOWEVER...
INFRARED IMAGERY INDICATES WARMING OF CLOUD TOPS AND THE CONVECTION
IS VERY POORLY ORGANIZED. DVORAK CLASSIFICATIONS STILL SUPPORT
TROPICAL STORM STRENGTH...AND ALTHOUGH THIS APPEARS TO BE GENEROUS
THE INITIAL INTENSITY REMAINS AT 35 KT. 
 
THE INITIAL MOTION FOR THIS ADVISORY IS 270/05. ALETTA HAS MAINTAINED
A WESTWARD MOTION FOR MUCH OF THE DAY. THE GLOBAL MODELS CONTINUE TO
BUILD A RIDGE TO THE NORTH AND WEST OF THE CYCLONE AND STEER ALETTA
WESTWARD...HOWEVER MOST OF THE GLOBAL MODELS DISSIPATE THE CYCLONE
WITHIN 72 HOURS. THE OFFICIAL TRACK FORECAST IS FASTER THAN THE
PREVIOUS ADVISORY AND FOLLOWS THE BAMM IN THE EXTENDED PERIOD.

ONLY A SMALL WINDOW EXISTS FOR ALETTA TO SLIGHTLY RE-STRENGTHEN AS
THE GLOBAL MODELS FORECAST THE SHEAR TO DECREASE IN THE NEXT 12
HOURS BEFORE INCREASING SHARPLY IN A DAY OR SO. ON THE OTHER
HAND...IF THE CURRENT CONVECTIVE TREND CONTINUES...ALETTA MAY WEAKEN
TO A TROPICAL DEPRESSION SOONER RATHER THAN LATER. THE INTENSITY
FORECAST FAVORS THE GFDL GUIDANCE...WHEREAS THE SHIPS MODEL IS
STRONGER BUT APPEARS UNREALISTIC DUE TO THE INCREASING SHEAR. AS A
RESULT OF THE IMPINGING DRY AIR AND FORECASTED INCREASED SHEAR IN
THE LATER PERIODS...THE CYCLONE IS LIKELY TO DISSIPATE TO A REMNANT
LOW WITHIN 4-5 DAYS...IF NOT SOONER.

FORECASTER MAINELLI/FRANKLIN
 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      29/2100Z 15.9N 102.1W    35 KT
 12HR VT     30/0600Z 15.9N 102.8W    40 KT
 24HR VT     30/1800Z 15.8N 103.7W    40 KT
 36HR VT     31/0600Z 15.8N 104.7W    35 KT
 48HR VT     31/1800Z 15.6N 105.7W    35 KT
 72HR VT     01/1800Z 15.5N 107.5W    30 KT
 96HR VT     02/1800Z 15.5N 109.0W    25 KT
120HR VT     03/1800Z 15.5N 111.0W    25 KT...REMNANT LOW
 
 
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