000 WTNT42 KNHC 270843 TCDAT2 TROPICAL STORM GUSTAV DISCUSSION NUMBER 9 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL072008 500 AM EDT WED AUG 27 2008 GUSTAV HAS BEEN HUGGING THE NORTH COAST OF SOUTHWESTERN HAITI THIS MORNING WITH STRONG BANDS OF THUNDERSTORMS TO THE EAST AND SOUTH OF THE CENTER. AN AIR FORCE RESERVE RECONNAISSANCE PLANE FOUND A MINIMUM PRESSURE OF 998 MB AND RELIABLE SFMR WINDS OF 45-50 KT. THE INITIAL INTENSITY WILL BE SET AT 50 KT. LITTLE INTENSIFICATION IS FORESEEN UNTIL THE CENTER MOVES FARTHER AWAY FROM THE HIGH TERRAIN OF HAITI. THEREAFTER...A STEADY INCREASE IN STRENGTH IS LIKELY... ESPECIALLY AFTER THE CENTER MOVES INTO THE MORE OPEN WATERS NORTHWEST OF JAMAICA. VERTICAL SHEAR IS FORECAST TO BE LIGHT...AND COMBINED WITH THE DEEP WARM WATERS...RAPID INTENSIFICATION COULD OCCUR IN A COUPLE OF DAYS WHILE THE CENTER IS NEAR OR SOUTH OF WESTERN CUBA. THE OFFICIAL FORECAST IS REDUCED FROM EARLIER DUE TO THE INITIAL WEAKENING BUT STILL SHOWS THE STORM BECOMING A MAJOR HURRICANE IN THE NORTHWESTERN CARIBBEAN SEA. IN THE LONGER-TERM... THE GLOBAL MODELS HAVE A VARIETY OF UPPER-WIND PATTERNS...BUT IN GENERAL THE UPPER WINDS APPEAR TO BE FAVORABLE ENOUGH TO SUPPORT A MAJOR HURRICANE IN THE GULF OF MEXICO. IT SHOULD BE NOTED THAT BOTH THE GFDL AND HWRF ARE MORE AGGRESSIVE THAN THE OFFICIAL FORECAST. THE STORM HAS NOT BEEN MOVING MUCH RECENTLY BUT AN AVERAGED OVER THE PAST TWELVE HOURS YIELDS AN ESTIMATE OF 300/4. A TURN TOWARD THE WEST IS LIKELY TODAY AS THE STORM BUMPS INTO A LARGE HIGH PRESSURE RIDGE OVER THE BAHAMAS AND FLORIDA. GUSTAV SHOULD THEN BE STEERED AROUND THE SOUTHERN PERIPHERY OF THE HIGH FOR THE NEXT SEVERAL DAYS AND TURN NORTHWESTWARD IN THE GULF OF MEXICO. THE OFFICIAL FORECAST IS VERY CLOSE THE PREVIOUS ONE AND IS JUST TO THE LEFT OF THE MODEL CONSENSUS. THE GFS IS AN EXTREME OUTLIER EARLY ON...TAKING THE STORM NEAR THE NORTH COAST OF CUBA...WHICH IS CONSIDERED VERY UNLIKELY AT THIS TIME. FORECAST POSITIONS AND MAX WINDS INITIAL 27/0900Z 18.6N 73.5W 50 KT 12HR VT 27/1800Z 19.0N 74.3W 50 KT 24HR VT 28/0600Z 19.1N 75.6W 60 KT 36HR VT 28/1800Z 19.2N 77.2W 70 KT 48HR VT 29/0600Z 19.6N 78.8W 80 KT 72HR VT 30/0600Z 21.0N 82.5W 100 KT 96HR VT 31/0600Z 23.5N 86.0W 105 KT 120HR VT 01/0600Z 27.0N 89.5W 105 KT $$ FORECASTER BLAKE/AVILA