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| #541430 (Received by flhurricane at: 10:38 PM 08.Sep.2012) TCDAT3 HURRICANE MICHAEL DISCUSSION NUMBER 24 NWS NATIONAL HURRICANE CENTER MIAMI FL AL132012 1100 PM AST SAT SEP 08 2012 MICHAEL HAS MAINTAINED A WELL-DEFINED EYE DURING THE PAST FEW HOURS...BUT THE AREAL COVERAGE OF THE COLDEST CONVECTIVE TOPS HAS BEEN DECREASING. BOTH SUBJECTIVE AND OBJECTIVE FINAL T-NUMBERS HAVE COME DOWN SINCE THE PREVIOUS ADVISORY...AND THE INTENSITY IS LOWERED TO 85 KT. THIS IS ALSO SUPPORTED BY THE MOST RECENT CI NUMBER GIVEN BY THE UW-CIMSS ADT. MICHAEL COULD FLUCTUATE IN INTENSITY DURING THE NEXT 24 HOURS SINCE ENVIRONMENTAL CONDITIONS ARE NOT EXPECTED TO CHANGE SUBSTANTIALLY FROM THEIR CURRENT STATES. HOWEVER...THE UPPER-LEVEL OUTFLOW FROM LESLIE COULD BEGIN TO AFFECT MICHAEL BY 48 HOURS...AND SEA SURFACE TEMPERATURES WILL BE FALLING TO NEARLY 20 DEGREES CELSIUS BY 72 HOURS. THEREFORE...FASTER WEAKENING IS FORECAST IN 2 TO 3 DAYS...AND THE INCREASINGLY UNFAVORABLE THERMODYNAMIC CONDITIONS SHOULD CAUSE MICHAEL TO BECOME POST-TROPICAL IN ABOUT 72 HOURS. THE CYCLONE IS THEN FORECAST TO BECOME ABSORBED BY A FRONT BY DAY 4...ALTHOUGH IT IS STILL UNCLEAR IF THE CULPRIT WILL BE THE WARM FRONT TO THE EAST OF LESLIE...AS SHOWN BY THE GFS...OR THE COLD FRONT TRAILING LESLIE...AS SHOWN BY THE ECMWF. MICHAEL HAS MAINTAINED ITS MOTION OF 335/5 KT...BUT THE HURRICANE IS EXPECTED TO TURN WESTWARD DURING THE NEXT 24 HOURS AS A LOW-/MID- LEVEL ANTICYCLONE BUILDS TO ITS NORTH. THE TRACK GUIDANCE ENVELOPE IS INDICATING A SHARPER TURN TO THE WEST THAN IT HAS IN PREVIOUS DAYS...AND THE NEW NHC FORECAST HAS BEEN SHIFTED A LITTLE SOUTH AND WEST OF THE PREVIOUS ONE MAINLY AT 36 AND 48 HOURS. THIS SOLUTION IS STILL TO THE RIGHT OF THE GFS/ECMWF/TVCA CLUSTERING AT THOSE TIMES. THE MODELS COME BACK TO BETTER AGREEMENT BY 72 HOURS ONCE MICHAEL IS ACCELERATING NORTHWARD AHEAD OF AN APPROACHING MID- LATITUDE TROUGH...EVEN THOUGH THAT IS A CASE WHERE YOU WOULD NORMALLY EXPECT TO SEE BIGGER TIMING DIFFERENCES. FORECAST POSITIONS AND MAX WINDS INIT 09/0300Z 33.4N 42.4W 85 KT 100 MPH 12H 09/1200Z 33.8N 42.8W 85 KT 100 MPH 24H 10/0000Z 33.9N 43.7W 80 KT 90 MPH 36H 10/1200Z 34.1N 45.0W 75 KT 85 MPH 48H 11/0000Z 35.2N 46.6W 65 KT 75 MPH 72H 12/0000Z 42.0N 47.0W 45 KT 50 MPH...POST-TROPICAL 96H 13/0000Z...ABSORBED BY A FRONT $$ FORECASTER BERG |
