000
WTNT43 KNHC 050840
TCDAT3
 
TROPICAL STORM MICHAEL DISCUSSION NUMBER   7
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL132012
500 AM AST WED SEP 05 2012
 
DEEP CONVECTION CONTINUES TO PULSATE NEAR AND EAST OF THE ESTIMATED
CENTER LOCATION...HOWEVER THE CONVECTIVE CANOPY IS SOMEWHAT
ELONGATED TOWARD THE NORTHEAST. THE INITIAL INTENSITY REMAINS 45 KT
IN AGREEMENT WITH THE LATEST SATELLITE ESTIMATES FROM TAFB AND SAB.
UW-CIMSS AND THE SHIPS MODEL INDICATE THAT WEST-NORTHWESTERLY SHEAR
OF ABOUT 20 KT IS AFFECTING THE CYCLONE...AND THIS SHEAR IS EXPECTED
TO CONTINUE FOR THE NEXT DAY OR SO. DURING THAT TIME...ONLY SLIGHT
STRENGTHENING IS SHOWN BY MOST OF THE INTENSITY GUIDANCE...AND THIS
TREND IS REFLECTED IN THE NHC FORECAST. THE SHEAR SHOULD BEGIN TO
DECREASE BY 48 HOURS...AND THE ENVIRONMENT APPEARS FAVORABLE FOR
SOME INTENSIFICATION BY THAT TIME. THE NEW NHC INTENSITY FORECAST
IS CLOSE TO THE IVCN INTENSITY CONSENSUS THROUGH THE PERIOD.

THE INITIAL MOTION ESTIMATE IS 360/04...AS MICHAEL APPEARS TO BE
RESPONDING TO A SHORTWAVE TROUGH PASSING TO THE NORTH. ONCE THE
TROUGH MOVES BY IN ABOUT 48 HOURS...THE GLOBAL MODELS SHOW A RIDGE
BUILDING TO THE NORTHWEST AND THEN TO THE NORTH OF THE TROPICAL
CYCLONE...WHICH SHOULD RESULT IN A SLOW NORTHWESTWARD MOTION AT
DAYS 3 THROUGH 5. THE NEW NHC TRACK IS ALONG BUT A LITTLE FASTER
THAN THE PREVIOUS FORECAST THROUGH 72 HOURS. AFTER THAT TIME THE
NHC FORECAST HAS BEEN SHIFTED A LITTLE TO THE RIGHT AND LIES
BETWEEN THE ECMWF AND GFS MODELS.

FORECAST POSITIONS AND MAX WINDS
 
INIT  05/0900Z 28.1N  43.9W   45 KT  50 MPH
 12H  05/1800Z 28.6N  43.7W   45 KT  50 MPH
 24H  06/0600Z 29.4N  43.1W   50 KT  60 MPH
 36H  06/1800Z 30.0N  42.6W   50 KT  60 MPH
 48H  07/0600Z 30.7N  42.8W   55 KT  65 MPH
 72H  08/0600Z 31.8N  43.7W   65 KT  75 MPH
 96H  09/0600Z 33.0N  45.0W   70 KT  80 MPH
120H  10/0600Z 34.0N  46.0W   65 KT  75 MPH
 
$$
FORECASTER BRENNAN