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| #541089 (Received by flhurricane at: 10:47 PM 07.Sep.2012) TCDAT3 HURRICANE MICHAEL DISCUSSION NUMBER 20 NWS NATIONAL HURRICANE CENTER MIAMI FL AL132012 1100 PM AST FRI SEP 07 2012 THE CLOUD PATTERN OF MICHAEL IN INFRARED IMAGERY HAS CONTINUED TO DEGRADE DURING THE PAST FEW HOURS...AND RECENT MICROWAVE DATA INDICATE THAT THE RING OF DEEP CONVECTION AROUND THE CENTER IS OPEN ON THE WEST SIDE. THE LATEST SUBJECTIVE DVORAK NUMBERS ARE T4.0/5.0 FROM BOTH TAFB AND SAB AND HAVE FALLEN TO T4.4/4.8 FROM THE UW-CIMSS ADT. THE INTENSITY IS THEREFORE LOWERED TO 85 KT. MICHAEL APPEARS TO HAVE BEEN SQUEEZED A BIT FROM THE NORTHWEST AND SOUTHEAST BY THE SURROUNDING UPPER-LEVEL FLOW...WHICH COULD BE CONTRIBUTING TO THE SLIGHT WEAKENING. HOWEVER...THE DEEP-LAYER SHEAR IS EXPECTED TO BE LIGHT FOR THE NEXT 36 HOURS...AND MICHAEL IS NOT FORECAST TO CHANGE MUCH IN INTENSITY DURING THAT TIME. THE OUTFLOW FROM LESLIE SHOULD PRODUCE STRONG NORTHERLY SHEAR ON THE ORDER OF 30-40 KT NEAR THE CYCLONE IN ABOUT 3 DAYS...AND MICHAEL IS EXPECTED TO SUFFER MARKEDLY GIVEN ITS SMALL SIZE. THE GLOBAL MODELS THEN SHOW MICHAEL RUNNING INTO A WARM FRONT BY DAY 4...WHILE OVER SEA SURFACE TEMPERATURES LESS THAN 20 DEGREES CELSIUS...SO THE CYCLONE IS FORECAST TO BE POST-TROPICAL AT 96 HOURS AND ABSORBED BY THE FRONT AT 120 HOURS. THE INITIAL MOTION ESTIMATE IS 310/4 KT. MICHAEL WILL CONTINUE TO MOVE SLOWLY NORTHWESTWARD DURING THE NEXT 48-72 HOURS WHILE BEING TRAPPED BETWEEN A RIDGE TO ITS EAST AND A DEVELOPING RIDGE TO ITS NORTH. AFTER 72 HOURS...THE CYCLONE WILL BECOME EMBEDDED IN THE SOUTHERLY FLOW TO THE EAST OF LESLIE...AND IT IS FORECAST TO ACCELERATE NORTHWARD UNTIL IT BECOMES ABSORBED WITHIN THE FRONTAL ZONE. THE TRACK MODELS ARE IN GENERALLY CLOSE PROXIMITY TO EACH OTHER DURING THE FORECAST PERIOD...AND THE ONLY REAL UPDATE NEEDED TO THE FORECAST WAS A SLIGHT SOUTHWESTWARD SHIFT OF THE 72-HOUR POINT. FORECAST POSITIONS AND MAX WINDS INIT 08/0300Z 31.8N 41.8W 85 KT 100 MPH 12H 08/1200Z 32.2N 42.1W 80 KT 90 MPH 24H 09/0000Z 32.9N 42.5W 80 KT 90 MPH 36H 09/1200Z 33.5N 43.0W 80 KT 90 MPH 48H 10/0000Z 33.9N 43.8W 75 KT 85 MPH 72H 11/0000Z 36.0N 46.5W 60 KT 70 MPH 96H 12/0000Z 44.0N 47.0W 55 KT 65 MPH...POST-TROPICAL 120H 13/0000Z...ABSORBED BY A FRONT $$ FORECASTER BERG |
