000
WTNT43 KNHC 110852
TCDAT3
 
TROPICAL STORM MICHAEL DISCUSSION NUMBER  33
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL132012
500 AM AST TUE SEP 11 2012
 
MICHAEL IS WEAKENING QUICKLY. DEEP CONVECTION HAS DECREASED IN BOTH
INTENSITY AND COVERAGE OVER THE LAST SEVERAL HOURS...AND MICROWAVE
DATA INDICATE THAT THE LOW-LEVEL CENTER IS DISPLACED TO THE
NORTHEAST OF THE REMAINING CONVECTION. DVORAK CLASSIFICATIONS HAVE
FALLEN BY A T-NUMBER...AND MICHAEL IS DOWNGRADED TO A TROPICAL
STORM WITH A WIND SPEED OF 55 KT...WHICH COULD STILL BE GENEROUS.
ADDITIONAL WEAKENING IS FORECAST TODAY AS THE STORM MOVES OVER
SUB-26C WATERS AND REMAINS IN AN UNFAVORABLE ATMOSPHERIC
ENVIRONMENT. THE CYCLONE WILL LIKELY BECOME POST-TROPICAL TONIGHT
OR EARLY WEDNESDAY WHEN IT IS EXPECTED TO BE OVER WATER
TEMPERATURES NEAR 20C AND IN STRONG SHEAR. THE GLOBAL MODELS ARE IN
GOOD AGREEMENT IN SHOWING THE POST-TROPICAL LOW MERGING WITH A COLD
FRONT BY WEDNESDAY NIGHT. THE NHC INTENSITY FORECAST FOLLOWS THE
MODEL CONSENSUS AND THE GUIDANCE PROVIDED BY THE OCEAN PREDICTION
CENTER.
 
THE TROPICAL STORM HAS TURNED NORTHWARD AND IS MOVING
FASTER...360/16. A TURN TO THE NORTH-NORTHEAST OR NORTHEAST WITH AN
ADDITIONAL INCREASE IN FORWARD SPEED IS PREDICTED OVER THE NEXT DAY
OR SO AS MICHAEL...OR ITS POST-TROPICAL LOW...BECOMES MORE EMBEDDED
IN STRONG FLOW BETWEEN A RIDGE TO ITS EAST AND A TROUGH TO ITS
WEST. THE NHC TRACK FORECAST IS A LITTLE FASTER THAN THE PREVIOUS
ONE AND BETWEEN THE GFS AND ECMWF MODELS.
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  11/0900Z 37.1N  47.7W   55 KT  65 MPH
 12H  11/1800Z 40.2N  46.7W   45 KT  50 MPH
 24H  12/0600Z 45.1N  43.2W   40 KT  45 MPH...POST-TROP/EXTRATROP
 36H  12/1800Z 50.9N  36.2W   40 KT  45 MPH...POST-TROP/EXTRATROP
 48H  13/0600Z...ABSORBED BY A FRONT
 
$$
FORECASTER CANGIALOSI