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| #541208 (Received by flhurricane at: 10:53 AM 08.Sep.2012) TCDAT3 HURRICANE MICHAEL DISCUSSION NUMBER 22 NWS NATIONAL HURRICANE CENTER MIAMI FL AL132012 1100 AM AST SAT SEP 08 2012 MICHAEL IS A LITTLE BETTER ORGANIZED ON SATELLITE IMAGERY WITH A SMALL EYE THAT HAS RECENTLY WARMED AND BECOME MORE DISTINCT. DVORAK ESTIMATES FROM SAB AND TAFB ARE 90 KT...WHICH ALSO MATCHES THE ADT ESTIMATE FROM CIMSS...SO THE WIND SPEED IS INCREASED TO THAT VALUE. THE BIGGEST NEGATIVE FACTOR FOR MICHAEL OVER THE NEXT COUPLE OF DAYS IS PROBABLY ITS SLOW FORWARD MOTION...WHICH IS UPWELLING SOME COOL WATER AND LIMITING ANY INTENISIFICATION. THIS CAN BE SEEN IN A RECENT BUOY NEAR THE CENTER THAT SHOWED AN SST OF ABOUT 78F. OTHERWISE...AN ENVIRONMENT OF LIGHT SHEAR AND GRADUALLY COOLING SSTS SHOULD PROMOTE ONLY A SMALL AMOUNT OF WEAKENING DURING THE NEXT DAY OR TWO. AFTER THAT TIME...MOST OF THE MODELS SHOW AN INCREASE IN NORTHERLY SHEAR...PARTIALLY RELATED TO OUTFLOW FROM LESLIE...ALONG WITH MICHAEL MOVING OVER COOLER WATERS. THUS A MORE RAPID WEAKENING IS LIKELY IN A FEW DAYS...AND THE COLD WATER SHOULD TURN MICHAEL INTO A POST-TROPICAL CYCLONE IN ABOUT 4 DAYS. THE NHC FORECAST IS A LITTLE HIGHER THAN THE PREVIOUS ONE FOR THE FIRST 24H...THEN IS BLENDED BACK WITH THE PREVIOUS PREDICTION AND THE INTENSITY CONSENSUS. A LONG-TERM MOTION ESTIMATE IS 325/4. THIS GENERAL MOTION IS EXPECTED FOR THE NEXT DAY OR SO UNTIL A HIGH PRESSURE RIDGE BUILDS NORTH OF THE CYCLONE...WHICH SHOULD CAUSE A TURN TO THE WEST-NORTHWEST. THE GLOBAL MODELS ALL HAVE A STRONGER RIDGE THAN YESTERDAY...AND EVEN SHOWING A WESTWARD MOTION OF THE HURRICANE IN A COUPLE OF DAYS. LATER ON...THIS HIGH SHOULD STRENGTHEN TO THE EAST OF MICHAEL...CAUSING THE CYCLONE TO THEN TURN TO THE NORTH AND ACCELERATE BY DAYS 3-4. THE MODEL GUIDANCE CONTINUES TO TREND WESTWARD...AND THE OFFICIAL FORECAST IS ADJUSTED IN THAT DIRECTION. MOST OF THE GLOBAL MODELS SHOW ENOUGH SEPARATION BETWEEN MICHAEL AND LESLIE SO THAT MICHAEL IS STEERED QUICKLY TO THE NORTH INTO A FRONTAL BOUNDARY...AND ABSORBED IN ABOUT 5 DAYS TIME. FORECAST POSITIONS AND MAX WINDS INIT 08/1500Z 32.6N 42.1W 90 KT 105 MPH 12H 09/0000Z 33.0N 42.5W 85 KT 100 MPH 24H 09/1200Z 33.4N 42.9W 85 KT 100 MPH 36H 10/0000Z 33.6N 43.8W 80 KT 90 MPH 48H 10/1200Z 33.8N 45.1W 75 KT 85 MPH 72H 11/1200Z 38.2N 48.2W 60 KT 70 MPH 96H 12/1200Z 48.0N 47.5W 50 KT 60 MPH...POST-TROPICAL 120H 13/1200Z...ABSORBED BY A FRONT $$ FORECASTER BLAKE |
