000 WTNT45 KNHC 290835 TCDAT5 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 $$ FORECASTER BLAKE/BRENNAN