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#208027 (Received by flhurricane at: 11:24 AM 17.Aug.2008) TCDAT1 TROPICAL STORM FAY DISCUSSION NUMBER 8 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL062008 1100 AM EDT SUN AUG 17 2008 FAY APPEARS A LITTLE RAGGED IN SATELLITE IMAGERY THIS MORNING...WITH THE MAIN CONVECTION IN BANDS WELL SOUTHEAST OF THE CENTER AND ONLY A SMALL AMOUNT OF CONVECTION NEAR THE CENTER. SATELLITE INTENSITY ESTIMATES FROM TAFB AND SAB ARE 45 AND 35 KT RESPECTIVELY...AND A SYNOPTIC OBSERVATION FROM CABO CRUZ CUBA REPORTED 45 KT. BASED ON THIS...THE INITIAL INTENSITY REMAINS 45 KT. THE INITIAL MOTION IS 290/11...A LITTLE MORE TO THE RIGHT THAN 6 HR AGO. FAY IS APPROACHING A DEVELOPING WEAKNESS IN A LOW/MID LEVEL RIDGE OVER THE GULF OF MEXICO...WHICH IS DEVELOPING DUE TO A MID/UPPER-LEVEL TROUGH OVER THE NORTHERN GULF COAST. THIS PATTERN SHOULD ALLOW FAY TO TURN MORE NORTHWARD AFTER 24 HR...BUT THERE REMAINS SIGNIFICANT DISAGREEMENT BETWEEN THE MODELS ON HOW MUCH OF A TURN WILL OCCUR. THE ECMWF...GFS...AND GFDL FORECAST A NORTHEASTWARD TURN TAKING FAY ACROSS THE FLORIDA PENINSULA INTO THE ATLANTIC. THE HWRF...UKMET...AND CANADIAN MODELS CALL FOR A NORTHWARD MOTION OVER OR JUST WEST OF THE FLORIDA PENINSULA INTO THE SOUTHEASTERN UNITED STATES. THEN...THE NOGPAS CALLS FOR A NORTH-NORTHWESTWARD MOTION TOWARD THE FLORIDA PANHANDLE. OVERALL...THE MODEL CONSENSUS HAS CHANGED LITTLE FOR THE FIRST 36-48 HR OF THE FORECAST PERIOD...THEN SHIFTED A LITTLE TO THE EAST THEREAFTER. THE NEW FORECAST TRACK IS THUS SIMILAR TO THE PREVIOUS TRACK FOR THE FIRST 48 HR...THEN SHIFTED A LITTLE TO THE EAST OF THE PREVIOUS TRACK. THE INTENSITY FORECAST REMAINS PROBLEMATIC. UPPER-LEVEL WINDS HAVE BECOME A LITTLE LESS FAVORABLE FOR DEVELOPMENT THIS MORNING...WITH THE SHIPS MODEL SHOWING 10 TO 15 KT OF WESTERLY VERTICAL WIND SHEAR. HOWEVER...THE SHEAR IS STILL LIGHT ENOUGH FOR STRENGTHENING TO OCCUR IF FAY CAN DEVELOP AN INNER CORE. THE SHIPS AND GFDL MODELS FORECAST FAY TO BE AT OR NEAR HURRICANE STRENGTH IN 36-48 HR...WHILE THE HWRF...WHICH KEEPS FAY OVER WATER LONGER...FORECASTS A BORDERLINE CATEGORY 1/2 HURRICANE IN 48-60. THE INTENSITY FORECAST CALLS FOR GRADUAL STRENGTHENING IN AGREEMENT WITH THE SHIPS MODEL...WITH FAY REACHING HURRICANE STRENGTH BEFORE LANDFALL ON THE WEST COAST OF FLORIDA. FAY COULD STRENGTHEN MORE THAN FORECAST IF A WELL-DEFINED INNER CORE FORMS...OR IF IT TRACKS MORE TO THE WEST AND STAYS LONGER OVER WATER. FORECAST POSITIONS AND MAX WINDS INITIAL 17/1500Z 20.5N 78.6W 45 KT 12HR VT 18/0000Z 21.3N 80.0W 50 KT 24HR VT 18/1200Z 22.9N 81.4W 55 KT...INLAND 36HR VT 19/0000Z 24.5N 82.0W 60 KT...OVER WATER 48HR VT 19/1200Z 26.2N 82.2W 70 KT 72HR VT 20/1200Z 29.5N 82.0W 50 KT...INLAND 96HR VT 21/1200Z 32.5N 81.5W 35 KT...INLAND 120HR VT 22/1200Z 36.0N 81.5W 20 KT...INLAND REMNANT LOW $$ FORECASTER BEVEN |