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Tropical Storm DELTA (Text)

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TROPICAL STORM DELTA DISCUSSION NUMBER  10
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
10 PM EST FRI NOV 25 2005
 
WIND SHEAR CONTINUES TO RESULT IN THE CONVECTION BEING RELEGATED TO
THE EASTERN SEMICIRCLE.  THE LOW-LEVEL CENTER IS ALMOST COMPLETELY
EXPOSED... BUT THE CONVECTION JUST TO ITS EAST IS STILL FAIRLY
DEEP.  A QUIKSCAT OVERPASS NEAR 2020Z REVEALED 45 KT WINDS JUST
OUTSIDE OF THE CONVECTION... AND THE CLOUD TOPS HAVE COOLED SINCE
THEN.  DVORAK INTENSITY ESTIMATES BASED ON A SHEAR PATTERN ARE
STILL T3.0/45 KT... AND THE ADVISORY INTENSITY IS MAINTAINED AT 50
KT.  HOWEVER... A STEADY WEAKENING TREND APPEARS IMMINENT... AS
WESTERLY WIND SHEAR IS FORECAST TO STRENGTHEN OVER DELTA DURING THE
NEXT 24-36 HOURS AHEAD OF A MID- TO UPPER-LEVEL TROUGH CURRENTLY
NORTH OF THE LESSER ANTILLES THAT WILL MOVE EASTWARD AND DEEPEN. 
THE NEW OFFICIAL FORECAST FOLLOWS THE SHIPS GUIDANCE CLOSELY IN
ANTICIPATING DELTA TO REMAIN A TROPICAL STORM FOR ONLY ABOUT 36
MORE HOURS.

DELTA HAS BEEN MOVING DUE SOUTHWARD AT ABOUT 6 KT FOR THE PAST
SEVERAL HOURS.  THE DYNAMICAL MODELS ARE UNANIMOUS IN FORECASTING
THIS MOTION TO CEASE SHORTLY AND FOR A NORTHEASTWARD MOTION TO
BEGIN SOMETIME WITHIN THE NEXT 24 HOURS.  THE MODELS ALSO FORECAST
A NEW SURFACE LOW PRESSURE SYSTEM TO FORM WEST OF DELTA IN 36-48
HOURS IN ASSOCIATION WITH THE MID/UPPER-LEVEL TROUGH APPROACHING
FROM THE WEST.  SINCE DELTA WILL PROBABLY WEAKEN QUITE A BIT DURING
THE NEXT COUPLE OF DAYS... IT IS NOT LIKELY TO MOVE AS QUICKLY
EASTWARD AS MOST OF THE MODELS ARE SUGGESTING... AND IT COULD EVEN
BE DRAWN WESTWARD INTO THE CIRCULATION OF THE NEW LOW PRESSURE
SYSTEM FORECAST TO DEVELOP.  HOWEVER... THE MODELS THAT DEPICT AN
APPROPRIATELY WEAK DELTA ALSO SUGGEST THERE IS ALSO A GOOD CHANCE
ITS CLOSED CIRCULATION WILL NOT SURVIVE BEYOND ABOUT 72 HOURS AS
BECOMES ENTANGLED IN A FRONTAL ZONE.  THIS IS THE SOLUTION SHOWN IN
THE OFFICIAL FORECAST.
 
FORECASTER KNABB
 
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      26/0300Z 21.9N  39.8W    50 KT
 12HR VT     26/1200Z 22.7N  39.3W    45 KT
 24HR VT     27/0000Z 23.8N  38.1W    35 KT
 36HR VT     27/1200Z 25.7N  36.1W    35 KT
 48HR VT     28/0000Z 28.2N  33.3W    30 KT...EXTRATROPICAL
 72HR VT     29/0000Z 29.5N  32.0W    30 KT...EXTRATROPICAL
 96HR VT     30/0000Z...ABSORBED BY FRONT
 
 
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