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#31373 (Received by flhurricane at: 11:03 AM 09.Jul.2005) TCDAT4 HURRICANE DENNIS DISCUSSION NUMBER 20 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 11 AM EDT SAT JUL 09 2005 SATELLITE...RADAR...AND NOAA RECONNAISSANCE DATA INDICATE DENNIS HAS SLOWLY BEEN GETTING BETTER ORGANIZED THIS MORNING. THE PRESSURE HAS BEEN GRADUALLY DECREASING SINCE DENNIS MOVED OFF THE NORTH COAST OF CUBA...BUT THIS HAS NOT BEEN REFLECTED BY A CORRESPONDING INCREASE IN FLIGHT-LEVEL WIND SPEEDS. THE EYE HAS BEEN RAGGED LOOKING MOST OF THIS MORNING IN THE KEY WEST DOPPLER RADAR DATA...ALTHOUGH IT HAS BECOME SLIGHTLY BETTER DEFINED IN THE LAST HOUR OR SO. THE INITIAL INTENSITY IS A BLEND OF RECON FLIGHT-LEVEL WINDS...SFMR DATA...AND SATELLITE INTENSITY ESTIMATES OF 77 KT AND 90 KT FROM TAFB AND SAB...RESPECTIVELY. THE INITIAL MOTION ESTIMATE IS 320/12. UPPER-AIR DATA AT 06Z AND ESPECIALLY AT 12Z...ALONG WITH WATER VAPOR IMAGERY...INDICATE THE MID- TO UPPER-LEVEL LOW OVER THE EXTREME NORTHWESTERN GULF JUST SOUTH OF LOUISIANA IS A LITTLE STRONGER THAN AND LARGER THAN ANY OF THE MODELS WERE INDICATING AT 00Z AND 06Z. THE NOGAPS MODEL DID NOT CAPTURE THIS FEATURE AT ALL...AND IT AND THE GFDN MODELS ARE THE ONLY MODELS THAT TAKE DENNIS TOWARD SOUTHEASTERN LOUISIANA. IT WOULD NOT SURPRISE ME IF THE 12Z MODELS SHIFT SLIGHTLY TO THE RIGHT GIVEN THAT THE LOW IS STRONGER THAN PREVIOUSLY FORECAST...AND THAT THE SUBTROPICAL RIDGE AXIS HAS CONTINUED TO SHIFT NORTHWARD AND IS NOW LOCATED ACROSS SOUTHEASTERN GEORGIA TO WESTERN TENNESSEE. THE OFFICIAL FORECAST IS JUST AN EXTENSION OF THE PREVIOUS TRACK. DENNIS IS CURRENTLY MOVING OVER A COOL EDDY...BUT IS EXPECTED TO MOVE BACK OVER WARMER WATER IN 12-18 HOURS. THE UPPER-LEVEL SHEAR IS EXPECTED TO REMAIN LOW AND THE OUTFLOW PATTERN IS FORECAST TO REMAIN QUITE IMPRESSIVE. THE SSTS AHEAD OF DENNIS ARE WARM ENOUGH TO SUPPORT A CATEGORY 3 HURRICANE UP UNTIL LANDFALL...SO THE ONLY INHIBITING FACTOR IS IF THE INNER-CORE STRUCTURE DOES NOT REGAIN ITS ORIGINAL STRUCTURE. BUT GIVEN THAT THE EYE DIAMETER IS ONLY 10-15 MILES...IT WOULD NOT TAKE MUCH CONVECTION TO DEVELOP AROUND THE EYE FOR DENNIS TO MAKE A SIGNIFICANT COMEBACK IN A SHORT PERIOD OF TIME. THE 64-KT WIND RADII WERE DECREASED BASED ON RECON DATA. FORECASTER STEWART FORECAST POSITIONS AND MAX WINDS INITIAL 09/1500Z 24.7N 83.8W 85 KT 12HR VT 10/0000Z 26.4N 85.0W 90 KT 24HR VT 10/1200Z 28.7N 86.4W 95 KT 36HR VT 11/0000Z 31.2N 87.7W 65 KT...INLAND 48HR VT 11/1200Z 33.6N 89.0W 30 KT...DISSIPATING INLAND 72HR VT 12/1200Z 36.5N 89.5W 20 KT...REMNANT LOW INLAND 96HR VT 13/1200Z 38.0N 88.0W 20 KT...REMNANT LOW INLAND 120HR VT 14/1200Z 39.0N 83.5W 20 KT...REMNANT LOW INLAND |