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#210811 (Received by flhurricane at: 4:43 PM 26.Aug.2008) TCDAT2 HURRICANE GUSTAV DISCUSSION NUMBER 7 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL AL072008 500 PM EDT TUE AUG 26 2008 AIR FORCE HURRICANE HUNTER REPORTS AND VISIBLE SATELLITE IMAGES...ON WHICH THE EYE OF THE HURRICANE BECAME EVIDENT...INDICATE THAT THE CENTER OF GUSTAV MADE LANDFALL AROUND 1730 UTC. A MINIMUM PRESSURE OF 992 MB WAS REPORTED BY THE AIRCRAFT JUST AS THE CENTER MOVED INLAND...HOWEVER A DROPSONDE RELEASED JUST EAST OF THE EYE HAD A SURFACE PRESSURE OF 997 MB WITH SOUTHERLY WINDS OF 64 KT. SO THE CENTRAL PRESSURE MAY HAVE BEEN SOMEWHAT LOWER THAN 992 MB. IN ANY EVENT...NOW THAT THE CENTER IS MOVING OVER THE MOUNTAINOUS TERRAIN OF THE SOUTHWEST PENINSULA OF HAITI...GUSTAV IS LIKELY LOSING STRENGTH. THE EYE IS NO LONGER EVIDENT ON SATELLITE IMAGES...AND THE SYSTEM COULD WEAKEN BELOW HURRICANE INTENSITY TONIGHT. HOWEVER THE UPPER-LEVEL ENVIRONMENT REMAINS FAVORABLE FOR INTENSIFICATION WITH ONLY A LITTLE NORTH-NORTHEASTERLY SHEAR...AND THEREFORE GUSTAV IS LIKELY TO REGAIN STRENGTH AS IT APPROACHES THE WINDWARD PASSAGE AND EASTERN CUBA TOMORROW. THE OFFICIAL INTENSITY FORECAST IS A BLEND OF THE SHIPS...LGEM...HWRF...AND GFDL GUIDANCE AND IS VERY SIMILAR TO THE PREVIOUS NHC WIND SPEED FORECAST. IT SHOULD BE RECALLED THAT BOTH SUBJECTIVE AND MODEL FORECASTS OF INTENSITY HAVE LITTLE SKILL IN THE 3- TO 5-DAY RANGE. INITIAL MOTION IS AROUND 305/9. THE MAIN PLAYER IN THE STEERING PATTERN FOR GUSTAV CONTINUES TO BE A MID-TROPOSPHERIC ANTICYCLONE/HIGH CENTERED NEAR THE FLORIDA PENINSULA. THE TROPICAL CYCLONE'S HEADING SHOULD GRADUALLY BEND TOWARD THE LEFT AS IT MOVES ALONG THE SOUTHERN PERIPHERY OF THIS ANTICYCLONE. LATER IN THE FORECAST PERIOD...GUSTAV IS EXPECTED TO TURN TOWARD THE NORTHWEST AS IT ROUNDS THE SOUTHWESTERN PERIPHERY OF THE HIGH. THE TRACK GUIDANCE MODELS ARE IN PRETTY GOOD AGREEMENT ON A GRADUAL TURN TOWARD THE WEST-NORTHWEST OVER THE NEXT DAY OR SO...AND OVERALL THE MODEL CONSENSUS HAS CHANGED LITTLE FROM THE PREVIOUS ADVISORY PACKAGE. THEREFORE THE TRACK FORECAST FOR THIS ADVISORY IS ESSENTIALLY AN EXTENSION OF THE PREVIOUS ONE. FORECAST POSITIONS AND MAX WINDS INITIAL 26/2100Z 18.4N 73.2W 65 KT 12HR VT 27/0600Z 18.9N 74.0W 75 KT 24HR VT 27/1800Z 19.3N 75.2W 80 KT 36HR VT 28/0600Z 19.5N 76.6W 85 KT 48HR VT 28/1800Z 19.6N 78.0W 90 KT 72HR VT 29/1800Z 20.3N 81.0W 100 KT 96HR VT 30/1800Z 22.5N 85.0W 105 KT 120HR VT 31/1800Z 25.5N 88.5W 105 KT $$ FORECASTER PASCH |