Tropical Storm SHARY

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TROPICAL STORM SHARY DISCUSSION NUMBER   2
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL   AL202010
500 AM AST FRI OCT 29 2010
 
ALTHOUGH THE CENTER OF SHARY IS PARTIALLY EXPOSED...A LARGE BURST OF
CONVECTION HAS FORMED ON THE WESTERN SIDE OF THE CIRCULATION.  THE
SYSTEM ALSO LOOKS A LITTLE MORE TROPICAL THAN EARLIER AS ITS
DISTANCE FROM THE UPPER-LEVEL LOW IS INCREASING AND THE CLOUD
PATTERN IS LESS DISTORTED.  SATELLITE INTENSITY ESTIMATES ARE 35 KT
FROM TAFB/SAB...AND THAT WILL BE THE INITIAL WIND SPEED.  THE
TROPICAL CYCLONE HAS ABOUT 24 HOURS LEFT FOR ANY INTENSIFICATION IN
AN ENVIRONMENT OF MARGINAL SSTS AND MODERATE SHEAR.  AFTER THAT
TIME...THE VERTICAL WIND SHEAR INCREASES DRAMATICALLY AS THE STORM
MOVES OVER COOLER WATERS.  SHARY IS EXPECTED TO BECOME
EXTRATROPICAL BY 36 HOURS AND SHOULD DISSIPATE AS IT IS ABSORBED
INTO A FRONTAL BOUNDARY BY DAY 3. THE MODEL GUIDANCE GENERALLY
SHOWS SOME STRENGTHENING IN THE SHORT TERM...AND THE OFFICIAL
FORECAST IS CLOSE TO THE PREVIOUS ONE.  NOTE THAT THE GFDL AND HWRF
BOTH SHOW SHARY BECOMING A HURRICANE IN A COUPLE OF DAYS...WHICH
SEEMS HIGHLY UNLIKELY GIVEN THE VERY STRONG SHEAR FORECAST AT THAT
TIME.
 
THE INITIAL MOTION ESTIMATE IS ABOUT 325/16...A BIT SLOWER THAN
EARLIER. SHARY IS EXPECTED TO TURN SHARPLY TOWARD THE NORTHEAST BY
EARLY SATURDAY AS RIDGING TO THE NORTH COLLAPSES AS A MID-LATITUDE
SWINGS THROUGH THE WESTERN ATLANTIC. THE GLOBAL MODELS ARE IN
RELATIVELY GOOD AGREEMENT ON THE TRACK OF THE STORM...THOUGH THE
SPEED DIFFERENCES REMAIN. THE NEW FORECAST WILL STAY ON THE SLOWER
SIDE OF THE MODEL CONSENSUS...BETWEEN THE SOLUTIONS OF THE GFS AND
ECMWF...AND IS RELATIVELY CLOSE TO THE PREVIOUS FORECAST.
 
FORECAST POSITIONS AND MAX WINDS
 
INITIAL      29/0900Z 28.5N  65.0W    35 KT
 12HR VT     29/1800Z 30.8N  65.1W    45 KT
 24HR VT     30/0600Z 33.9N  62.0W    45 KT
 36HR VT     30/1800Z 37.7N  56.3W    45 KT...POST-TROP/EXTRATROP
 48HR VT     31/0600Z 42.5N  48.5W    40 KT...POST-TROP/EXTRATROP
 72HR VT     01/0600Z...DISSIPATED
 
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FORECASTER BLAKE/BRENNAN
 
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