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TROPICAL STORM DOLLY DISCUSSION NUMBER  11
NATIONAL WEATHER SERVICE MIAMI FL
11 PM EDT SAT AUG 31 2002

DOLLY HAS CHANGED LITTLE OVER THE PAST SEVERAL HOURS...MAINTAINING
AN OVERALL LARGE CYCLONIC ENVELOPE WITH BURSTS OF CONVECTION
TO THE NORTH AND WEST OF THE CENTER.  SATELLITE INTENSITY ESTIMATES
ARE 35 KT FROM TAFB...SAB...AND AFWA...SO THAT REMAINS THE INITIAL
INTENSITY.

THE LOW LEVEL CENTER IS VERY DIFFICULT TO LOCATE...AND THE
INITIAL MOTION IS A VERY UNCERTAIN 285/19.  THERE IS LITTLE CHANGE
IN THE FORECAST PHILOSOPHY FROM THE LAST PACKAGE.  DOLLY IS SOUTH
OF AN LOW/MID LEVEL RIDGE THAT WILL GRADUALLY WEAKEN AS LARGE-SCALE
TROUGHING DEVELOPS OVER THE WESTERN ATLANTIC.  THIS SHOULD CAUSE
THE CYCLONE TO GRADUALLY CURVE MORE NORTHWARD WITH TIME.  THIS IS
REFLECTED IN ALL TRACK GUIDANCE SAVE CLIPER AND NHC90UK...WHICH ARE
WEST-NORTHWESTWARD OUTLIERS.  THE OFFICIAL FORECAST WILL CALL
FOR A GRADUAL NORTHWARD TURN WITH TIME.  DUE MAINLY TO THE 
CONTINUED QUICK MOTION AND THE POSSIBILITY THAT A WEAK SHALLOW
SYSTEM MAY NOT TURN AS QUICKLY NORTHWARD...THE TRACK IS SOMEWHAT TO
THE LEFT OF THE PREVIOUS FORECAST AND ALONG THE LEFT SIDE OF THE 
GUIDANCE.

DOLLY IS APPROACHING SOUTHWESTERLY UPPER-LEVEL FLOW...THE BEGINNING
OF INCREASED SHEAR FORECAST BY THE LARGE-SCALE MODELS SEVERAL DAYS
AGO.  ALTHOUGH THE SHIPS MODEL NOTES THE INCREASE IN SHEAR...IT
STILL CALLS FOR INTENSIFICATION.  THE GFDL...THE OTHER EXTREME...
DISSIPATES DOLLY IN 12 HR.  THE INTENSITY FORECAST CALLS FOR
DOLLY TO HANG ON AS A TROPICAL STORM SINCE THERE ARE NOT YET ANY
INTERNAL SIGNS THAT IT IS DISSIPATING AND SINCE A MORE NORTHERLY
TRACK MIGHT REDUCE THE IMPACT OF THE SOUTHWESTERLY UPPER FLOW.
HOWEVER...IT WOULD NOT BE A SURPRISE TO SEE DOLLY DISSIPATE DUE TO
SHEAR BEFORE 72 HR.

FORECASTER BEVEN
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL     01/0300Z 13.8N  47.6W    35 KTS
12HR VT     01/1200Z 14.7N  50.2W    35 KTS
24HR VT     02/0000Z 16.0N  52.6W    35 KTS
36HR VT     02/1200Z 17.5N  54.4W    35 KTS
48HR VT     03/0000Z 19.1N  55.3W    35 KTS
72HR VT     04/0000Z 21.5N  56.0W    35 KTS
 
 
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