000
WTNT43 KNHC 042052
TCDAT3
 
TROPICAL STORM MICHAEL DISCUSSION NUMBER   5
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL132012
500 PM AST TUE SEP 04 2012
 
MICHAEL HAS BECOME BETTER ORGANIZED DURING THE DAY.  ALTHOUGH
GEOSTATIONARY SATELLITE IMAGES INDICATE SOME WARMING OF THE CLOUD
TOPS DURING THE PAST HOUR OR SO...RECENT MICROWAVE DATA INDICATE
THAT A CURVED BAND NOW WRAPS ABOUT THREE-QUARTERS OF THE WAY AROUND
THE CENTER.  THE INITIAL WIND SPEED IS SET AT 45 KT...BASED ON
DVORAK CLASSIFICATIONS FROM BOTH TAFB AND SAB AND DATA FROM AN
EARLIER PARTIAL ASCAT PASS THAT SHOWED A COUPLE OF 35 TO 40 KT WIND
VECTORS JUST NORTHWEST OF THE CENTER.  ONLY SLIGHT ADDITIONAL
STRENGTHENING IS FORECAST IN THE SHORT TERM AS WESTERLY SHEAR IS
EXPECTED TO INCREASE OVER THE SMALL CYCLONE DURING THE NEXT DAY OR
TWO.  AFTER THAT TIME...HOWEVER...AN UPPER-LEVEL LOW IS EXPECTED TO
CUT OFF TO THE SOUTHWEST OF MICHAEL.  AS THAT OCCURS...A NARROW
RIDGE IS EXPECTED TO BUILD OVER THE CYCLONE...RESULTING IN A
REDUCTION OF VERTICAL SHEAR.  THE OFFICIAL INTENSITY FORECAST IS
INCREASED FROM THE PREVIOUS ADVISORY AND LIES FAIRLY CLOSE TO...BUT
A LITTLE LOWER THAN...THE SHIPS AND LGEM GUIDANCE.

MICHAEL IS MOVING SLOWLY NORTH-NORTHWESTWARD...BUT IS EXPECTED TO
TURN TOWARD THE NORTHEAST IN A DAY OR SO AS A MID-LATITUDE TROUGH
MOVES EASTWARD ACROSS THE CENTRAL ATLANTIC.  AFTER THIS TOUGH
BYPASSES MICHAEL...A RIDGE IS FORECAST TO BUILD OVER THE CENTRAL
ATLANTIC TO THE NORTH OF THE CYCLONE.  AS THE RIDGE SLIDES
EASTWARD IN A FEW DAYS...IT SHOULD CAUSE MICHAEL TO TURN
NORTHWESTWARD.  THE TRACK GUIDANCE IS IN GENERAL AGREEMENT ON 
THIS SCENARIO AND THE OFFICIAL FORECAST LIES BETWEEN THE MODEL
CONSENSUS AND THE PREVIOUS NHC TRACK.
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  04/2100Z 27.5N  43.7W   45 KT  50 MPH
 12H  05/0600Z 28.1N  43.9W   50 KT  60 MPH
 24H  05/1800Z 28.8N  43.8W   50 KT  60 MPH
 36H  06/0600Z 29.4N  43.3W   50 KT  60 MPH
 48H  06/1800Z 29.9N  42.9W   50 KT  60 MPH
 72H  07/1800Z 30.9N  43.2W   55 KT  65 MPH
 96H  08/1800Z 32.0N  44.0W   60 KT  70 MPH
120H  09/1800Z 33.5N  46.0W   60 KT  70 MPH
 
$$
FORECASTER BROWN