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#46373 (Received by flhurricane at: 4:38 PM 16.Sep.2005) TCDAT1 TROPICAL STORM OPHELIA DISCUSSION NUMBER 43 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 5 PM EDT FRI SEP 16 2005 OPHELIA HAS SOMEWHAT RE-ORGANIZED DURING THE DAY...WITH THE CONVECTION MAKING OCCASIONAL ATTEMPTS TO WRAP AROUND THE WEST SIDE OF THE LOW-LEVEL CENTER. NOAA AND AIR FORCE RESERVE HURRICANE HUNTER AIRCRAFT INDICATE THE CENTRAL PRESSURE HAS FALLEN TO 993 MB. THE NOAA PLANE MEASURED 73 KT AT 700 MB...AND A 59 KT SURFACE WIND OFF THE STEPPED FREQUENCY MICROWAVE RADIOMETER. HOWEVER...THE MAXIMUM WIND OBSERVED THUS FAR BY THE AIR FORCE AIRCRAFT AT 59 MB IS 59 KT. THERE IS ALSO A REPORT OF 74 KT AT 2500 FT FROM THE FIRST-EVER SUCCESSFUL AEROSONDE FLIGHT INTO THE CORE OF A TROPICAL CYCLONE. BASED ON ALL THIS DATA...THE INITIAL INTENSITY IS INCREASED TO 55 KT. OPHELIA HAS TURNED RIGHT AND ACCELERATED WITH AN INITIAL MOTION OF 040/11. THE STORM IS BECOMING EMBEDDED IN THE WESTERLIES...AND AS A HIGH PRESSURE SYSTEM TO THE EAST BREAKS DOWN THE STORM SHOULD TURN NORTHEASTWARD AND ACCELERATE. THIS SHOULD BE FOLLOWED AFTER 72 HR BY A MORE EASTWARD MOTION AT HIGH LATITUDE. THE TRACK GUIDANCE IS TIGHTLY CLUSTERED THROUGH 48 HR...AND THE NEW FORECAST TRACK IS DOWN THE MIDDLE OF THE GUIDANCE. THE NEW TRACK IS AGAIN A LITTLE TO THE LEFT OF THE OLD TRACK...PARTICULARLY AFTER 24 HR. WHILE LITTLE CHANGE IN STRENGTH IS FORECAST DURING THE NEXT 12-24 HR...SOME SLIGHT STRENGTHENING COULD OCCUR BEFORE OPHELIA CROSSES THE NORTH WALL OF THE GULF STREAM IN 12-18 HR. AFTER THAT...COLDER WATER...INCREASING SHEAR...AND THE ONSET OF EXTRATROPICAL TRANSITION SHOULD CAUSE WEAKENING. OPHELIA IS EXPECTED TO LOSE TROPICAL CHARACTERISTICS IN ABOUT 36 HR. FORECASTER BEVEN FORECAST POSITIONS AND MAX WINDS INITIAL 16/2100Z 36.8N 73.2W 55 KT 12HR VT 17/0600Z 38.7N 71.7W 55 KT 24HR VT 17/1800Z 41.6N 68.5W 55 KT 36HR VT 18/0600Z 45.2N 63.6W 50 KT...INLAND EXTRATROPICAL 48HR VT 18/1800Z 48.0N 57.3W 45 KT...INLAND EXTRATROPICAL 72HR VT 19/1800Z 51.5N 43.0W 45 KT...EXTRATROPICAL 96HR VT 20/1800Z 53.5N 27.0W 40 KT...EXTRATROPICAL 120HR VT 21/1800Z 55.0N 14.0W 40 KT...EXTRATROPICAL |