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| #54227 (Received by flhurricane at: 5:03 AM 27.Oct.2005) TCDAT1 TROPICAL STORM BETA DISCUSSION NUMBER 2 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL 5 AM EDT THU OCT 27 2005 AS OFTEN OCCURS AS A DEPRESSION EVOLVES INTO A TROPICAL STORM... THE OUTER BANDS FROM LAST NIGHT HAVE DISSIPATED WHILE BURSTS OF DEEP CONVECTION HAVE CONSOLIDATED NEAR THE CIRCULATION CENTER. SATELLITE INTENSITY ESTIMATES ARE UNANIMOUSLY 35 KT...AND THEY ARE ONLY THAT LOW DUE TO DVORAK CONSTRAINTS. THE CONVECTIVE PATTERN APPEARS TO CORRESPOND TO AN EVEN STRONGER SYSTEM...BUT THE WINDS HAVE PROBABLY NOT YET CAUGHT UP TO THE CLOUD SIGNATURE. THE DEPRESSION IS UPGRADED TO A TROPICAL STORM WITH 35 KT WINDS... MAKING BETA THE RECORD-SETTING 23RD TROPICAL STORM OF THE 2005 SEASON. THE SLOW NORTHWESTWARD MOTION OF ABOUT 5 KT IS BEING PROVIDED BY WEAK SOUTHEASTERLY FLOW... IN BETWEEN A LARGE AND DEEP LAYER ANTICYCLONE CENTERED A DISTANT 2000 N MI TO THE EAST-NORTHEAST OVER THE CENTRAL ATLANTIC... AND A MID/UPPER LEVEL SHORTWAVE TROUGH OVER THE GULF OF MEXICO. MOST OF THE MODELS FORECAST ENOUGH RIDGING TO DEVELOP IN PLACE OF THE SHORTWAVE TROUGH OVER THE SOUTHERN GULF TO EVENTUALLY TURN BETA WESTWARD INTO NICARAGUA...BUT THERE IS SUBSTANTIAL DISAGREEMENT ON WHEN THAT TURN WILL OCCUR. OVERALL THE MODELS HAVE SLOWED DOWN COMPARED TO THE PREVIOUS CYCLE...AND NONE OF THEM BRING THE CENTER ONSHORE IN LESS THAN 48 HOURS. THE OFFICIAL FORECAST IS KEPT ALONG THE SAME PATH OF THE PREVIOUS ADVISORY...BUT SLOWED DOWN TO NUDGE TOWARD THE GUIDANCE. OCEANIC AND ATMOSPHERIC CONDITIONS APPEAR FAVORABLE FOR STRENGTHENING... WITH SEA SURFACE TEMPERATURES EXCEEDING 29 CELSIUS AND VERY WEAK VERTICAL WIND SHEAR EXPECTED TO PERSIST ALONG THE OFFICIAL FORECAST TRACK. THE SHIPS GUIDANCE SUGGESTS BETA COULD BE NEAR HURRICANE STRENGTH IN ABOUT 48 HOURS IF IT HAS NOT YET MADE LANDFALL... AND THE RAPID INTENSIFICATION INDEX BASED ON SHIPS INDICATES NEARLY A 50/50 SHOT AT 25 KT OF STRENGTHENING DURING THE FIRST 24 HOURS. THE GFDL FORECASTS EVEN MORE INTENSIFICATION...TO HURRICANE STRENGTH WITHIN 36 HOURS. SINCE THE NEW OFFICIAL TRACK FORECAST KEEPS BETA OVER WATER LONGER THAN THE PREVIOUS ADVISORY...AND GIVEN THE VERY BULLISH GUIDANCE...THE NEW OFFICIAL INTENSITY FORECAST IS ADJUSTED UPWARD AND ANTICIPATES A HURRICANE BY THE TIME OF LANDFALL ON THE NICARAGUAN COAST. FURTHER... SINCE THE 36 HOUR FORECAST IS NEAR HURRICANE STRENGTH... IT IS CERTAINLY POSSIBLE THAT HURRICANE CONDITIONS COULD OCCUR WITHIN 36 HOURS IN THE AREAS ALREADY UNDER A TROPICAL STORM WARNING. HOWEVER...WE HAVE NOT YET BEEN ABLE TO CONTACT NICARAGUA REGARDING THE ISSUANCE OF A HURRICANE WATCH IN ADDITION TO THE TROPICAL STORM WARNING. FORECASTER KNABB FORECAST POSITIONS AND MAX WINDS INITIAL 27/0900Z 11.4N 81.8W 35 KT 12HR VT 27/1800Z 11.8N 82.2W 45 KT 24HR VT 28/0600Z 12.5N 82.6W 55 KT 36HR VT 28/1800Z 12.8N 83.0W 60 KT 48HR VT 29/0600Z 13.0N 83.6W 65 KT...INLAND 72HR VT 30/0600Z 13.0N 85.0W 30 KT...INLAND 96HR VT 31/0600Z...DISSIPATED |
