Hurricane MICHAEL
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HURRICANE MICHAEL DISCUSSION NUMBER 25
NWS NATIONAL HURRICANE CENTER MIAMI FL AL132012
500 AM AST SUN SEP 09 2012
THE EYE OF THE SMALL HURRICANE REMAINS DISTINCT AND COLD CLOUD TOPS
SURROUND THE CENTER...THOUGH THERE HAVE BEEN OCCASIONALLY BREAKS IN
THE CONVECTIVE PATTERN. RECENT GEOSTATIONARY SATELLITE AND
MICROWAVE IMAGES SUGGEST THAT THE EYEWALL IS A LITTLE WIDER THAN IT
WAS LAST NIGHT. DVORAK CLASSIFICATIONS WERE ESSENTIALLY
UNCHANGED...THEREFORE...THE THE INITIAL WIND SPEED IS HELD AT 85
KT.
MICHAEL STILL LIES OVER RELATIVELY WARM WATER AND IN A FAVORABLE
UPPER-LEVEL WIND PATTERN...BUT THESE CONDITIONS ARE EXPECTED TO
CHANGE OVER THE NEXT FEW DAYS. WATER VAPOR IMAGES AND SATELLITE
DERIVED WINDS SHOW STRONG NORTHERLY FLOW ALOFT...IN PART ASSOCIATED
WITH THE OUTFLOW OF LESLIE...LOCATED A FEW HUNDRED N MI TO THE WEST
OF MICHAEL. THIS FLOW IS EXPECTED TO BEGIN AFFECTING THE HURRICANE
WITHIN THE NEXT 24 HOURS...WHICH SHOULD CAUSE SOME WEAKENING. IN 2
TO 3 DAYS...THE SHIPS MODEL SHOWS NORTHERLY SHEAR INCREASING TO
NEAR 30 KT AND MICHAEL IS EXPECTED TO BE OVER COOL WATERS BY THEN.
THESE HOSTILE CONDITIONS SHOULD CAUSE A FASTER RATE OF WEAKENING
AND A TRANSITION TO A POST-TROPICAL CYCLONE. THE INTENSITY FORECAST
IS AN UPDATE OF THE PREVIOUS ONE AND IN AGREEMENT WITH MOST OF
THE GUIDANCE.
MICHAEL IS MOVING NORTHWESTWARD AT ABOUT 4 KT. A MID-LEVEL RIDGE IS
EXPECTED TO BUILD TO THE NORTH OF THE HURRICANE LATER TODAY AND
TONIGHT...AND THAT SHOULD CAUSE THE SYSTEM TO TURN WESTWARD.
MICHAEL IS FORECAST TO THEN GRADUALLY TURN NORTHWARD AS IT MOVES
INTO STRONG SOUTHERLY STEERING FLOW ON THE WESTERN SIDE OF THE RIDGE
TO THE EAST OF A HIGH AMPLITUDE TROUGH. THE GLOBAL MODELS SHOW
MICHAEL BECOMING ABSORBED WITHIN A FRONTAL ZONE IN 3 TO 4 DAYS. THE
TRACK FORECAST HAS BEEN NUDGED TO THE WEST AND LIES FAIRLY CLOSE TO
THE TVCA CONSENSUS.
FORECAST POSITIONS AND MAX WINDS
INIT 09/0900Z 33.8N 42.7W 85 KT 100 MPH
12H 09/1800Z 33.9N 43.5W 80 KT 90 MPH
24H 10/0600Z 34.0N 44.8W 75 KT 85 MPH
36H 10/1800Z 34.6N 46.6W 70 KT 80 MPH
48H 11/0600Z 36.5N 47.9W 60 KT 70 MPH
72H 12/0600Z 45.5N 45.5W 45 KT 50 MPH...POST-TROPICAL
96H 13/0600Z...ABSORBED BY A FRONT
$$
FORECASTER CANGIALOSI
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