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| #9672 (Received by flhurricane at: 4:58 AM 23.Sep.2004) TCDAT1 HURRICANE JEANNE DISCUSSION NUMBER 39 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 5 AM EDT THU SEP 23 2004 INFRARED IMAGERY SINCE THE SATELLITE ECLIPSE PERIOD SHOW THAT CLOUD TOPS HAVE COOLED AROUND THE EYE OF JEANNE...BUT THAT THE EYE HAS BECOME MORE CLOUD FILLED. SATELLITE INTENSITY ESTIMATES REMAIN 90 KT FROM ALL AGENCIES...SO THE INITIAL INTENSITY WILL REMAIN 85 KT. CIRRUS OUTFLOW IS CURRENTLY GOOD IN THE NORTHWESTERN QUADRANT AND FAIR TO POOR ELSEWHERE. POST-ECLIPSE IMAGES SHOW THAT JEANNE HAS MOVED VERY LITTLE SINCE 0315Z...PERHAPS JUST A LITTLE WESTWARD. THE INITIAL MOTION IS A SOMEWHAT UNCERTAIN 260/3. A DEEP-LAYER ANTICYCLONE OVER THE EASTERN UNITED STATES IS MOVING EASTWARD OR BUILDING INTO THE ATLANTIC...AND LARGE SCALE MODELS FORECAST THIS TO CONTINUE THROUGH 72 HR. THIS SHOULD MOVE JEANNE IN A GENERAL WESTERLY DIRECTION WITH ACCELERATION. AFTER 72 HR...JEANNE BECOMES LOCATED SOUTHWEST OF THE ANTICYCLONE...WHICH BEGINS TO ELONGATE NORTH-SOUTH. THIS WOULD ALLOW A NORTHWARD TURN AND EVENTUAL RECURVATURE INTO THE WESTERLIES. AS IS OFTEN THE CASE...THE QUESTION IS WHERE WILL THE TURN OCCUR. THE NOGAPS AND THE UKMET FORECAST THE TURN TO OCCUR AFTER JEANNE HAS HIT SOUTHEASTERN FLORIDA. THE GFS...GFDL... AND CANADIAN FORECAST AN EARLIER TURN...WHICH WOULD BRING JEANNE NEAR OR OVER EAST CENTRAL OR NORTHEASTERN FLORIDA. THE DIFFERENCE IN THE MODELS SEEMS TO BE THE FORWARD SPEED...WITH THE FASTER UKMET AND NOGAPS REACHING SOUTHEASTERN FLORIDA...WHILE THE OTHER MODELS HAVE A SLOWER WESTWARD MOTION AND DO NOT BRING JEANNE AS FAR WEST BEFORE THE TURN. WHILE THE NOGAPS SOLUTION CANNOT BE RULED OUT...THE UKMET HAS JEANNE AT 70.8W AT 1200Z THIS MORNING AND THUS APPEARS TOO FAST. THE FORECAST TRACK IS SHIFTED WESTWARD FROM THE PREVIOUS TRACK AND NOW CALLS FOR LANDFALL IN EAST CENTRAL FLORIDA. IT IS ALONG THE LINE OF THE MODEL CONSENSUS BUT A LITTLE SLOWER. THE INTENSITY FORECAST REMAINS TRICKY. JEANNE IS CURRENTLY OVER SEA SURFACE TEMPERATURES OF ABOUT 27C...LIKELY BROUGHT ABOUT BY UPWELLING CAUSED BY THE SLOW-MOVING HURRICANE. SINCE JEANNE REMAINS SLOW MOVING...THIS SUGGESTS THAT THE CURRENT INCREASE IN CONVECTIVE ORGANIZATION MAY BE TEMPORARY. ONLY SLOW STRENGTHENING IS LIKELY WHILE JEANNE REMAINS EAST OF 72W. THE WATERS ARE ABOUT 28C WEST OF 72W...AND WHEN JEANNE REACHES THEM IT SHOULD BE IN A RATHER FAVORABLE UPPER-LEVEL WIND PATTERN. THUS...THE INTENSITY FORECAST SHOWS STRENGTHENING. INTENSITY GUIDANCE IS STILL RELUCTANT TO FORECAST JEANNE MUCH ABOVE 95-100 KT...AND THE INTENSITY FORECAST WILL SHOW 95 KT IN AGREEMENT WITH THIS. HOWEVER...IT WOULD BE NO SURPRISE TO SEE JEANNE REACH MAJOR HURRICANE STATUS IN 48-72 HR. AFTER 72 HR...LAND INTERACTION AND INCREASING SHEAR SHOULD PRODUCE SIGNIFICANT WEAKENING. GIVEN THE FORECAST OF THE STEERING CURRENTS...FLORIDA SHOULD PAY CLOSE ATTENTION TO THE EVOLUTION OF JEANNE. FORECASTER BEVEN FORECAST POSITIONS AND MAX WINDS INITIAL 23/0900Z 25.5N 69.5W 85 KT 12HR VT 23/1800Z 25.4N 70.5W 85 KT 24HR VT 24/0600Z 25.4N 72.1W 90 KT 36HR VT 24/1800Z 25.6N 74.0W 90 KT 48HR VT 25/0600Z 26.0N 75.9W 95 KT 72HR VT 26/0600Z 27.0N 79.5W 95 KT 96HR VT 27/0600Z 29.5N 81.5W 85 KT...INLAND 120HR VT 28/0600Z 34.0N 80.0W 75 KT...INLAND |
