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#3875 (Received by flhurricane at: 4:36 AM 05.Aug.2004) TCDAT1 HURRICANE ALEX DISCUSSION NUMBER 20 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 5 AM EDT THU AUG 05 2004 ALEX REMAINS WELL ORGANIZED THIS MORNING...WITH A WELL-DEFINED EYE SURROUNDED BY CONVECTIVE TOPS OF -65C TO -75C. INDEED...THE CLOUD TOPS HAVE COOLED SOMEWHAT OVER THE PAST FEW HOURS. SATELLITE INTENSITY ESTIMATES ARE 102 KT FROM ALL AGENCIES. BASED ON THIS...THE MAXIMUM WINDS REMAIN 105 KT. THE UPPER-LEVEL OUTFLOW IS FAIR IN THE NORTHEASTERN SEMICIRCLE AND POOR ELSEWHERE. THE INITIAL MOTION IS NOW 065/25. ALEX IS WELL EMBEDDED IN THE WESTERLIES AND SHOULD CONTINUE AN ACCELERATING EAST-NORTHEASTWARD MOTION FOR 24 HR OR SO...FOLLOWED BY A GRADUAL TURN TOWARD THE EAST. ALL TRACK GUIDANCE AGREES WITH THIS SCENARIO OUT TO 48-72 HR...AND THE OFFICIAL FORECAST IS AN UPDATE OF THE PREVIOUS PACKAGE. THE CLOUD TOP COOLING CURRENTLY OCCURRING IS LIKELY TO BE THE LAST GASP FOR ALEX. THE HURRICANE SHOULD MOVE NORTH OF THE GULF STREAM INTO MUCH COLDER SEA SURFACE TEMPERATURES DURING THE NEXT 12-18 HOURS WHICH SHOULD CAUSE SIGNIFICANT WEAKENING. ALEX WILL BEGIN EXTRATROPICAL TRANSITION AFTER 24 HR AND COMPLETE IT BY 48 HR. WHILE DETAILS DIFFER...ALL LARGE-SCALE MODELS AGREE THAT EXTRATROPICAL ALEX WILL MERGE WITH EITHER ANOTHER EXTRATROPICAL LOW OR A COLD FRONT BY 72 HR AND LOSE ITS IDENTITY...AND THE INTENSITY FORECAST FOLLOWS THIS SCENARIO. FORECASTER BEVEN FORECAST POSITIONS AND MAX WINDS INITIAL 05/0900Z 40.0N 61.5W 105 KT 12HR VT 05/1800Z 42.0N 56.2W 95 KT 24HR VT 06/0600Z 45.0N 46.5W 75 KT 36HR VT 06/1800Z 47.0N 36.5W 60 KT...BECOMING EXTRATROPICAL 48HR VT 07/0600Z 47.0N 26.5W 55 KT...EXTRATROPICAL 72HR VT 08/0600Z...ABSORBED BY EXTRATROPICAL LOW |