000
WTNT43 KNHC 092033
TCDAT3
 
HURRICANE MICHAEL DISCUSSION NUMBER  27
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL132012
500 PM AST SUN SEP 09 2012
 
THE MIXING EVENT ACTIVE WITHIN THE INNER CORE OF MICHAEL APPEARS TO
BE NEAR COMPLETION....AND A TRANSFORMATION HAS TAKEN PLACE. THE EYE
OF THE CYCLONE HAS BECOME MORE RAGGED AND CLOUD- FILLED SINCE THIS
MORNING...WITH ITS DIAMETER MEASURING 30 N MI AFTER BEING AROUND 10
N MI ABOUT 12 HOURS AGO. THE CLOUD PATTERN IS NO LONGER
SYMMETRIC...AND CLOUD TOP TEMPERATURES CONTINUE TO WARM. DVORAK
T-NUMBERS ARE UNCHANGED AT 4.5 FROM TAFB AND SAB...AND THE ADT CI
VALUE IS 5.2. THE INITIAL INTENSITY IS KEPT AT 80 KT IN AGREEMENT
WITH A BLEND OF THESE DATA.
 
MICHAEL HAS BEEN MOVING DUE WEST SINCE THIS MORNING...AND HAS
EVEN WOBBLED A BIT SOUTH OF WEST IN RECENT HOURS.  THE INITIAL
MOTION ESTIMATE...A LONGER-TERM AVERAGE...IS 270/04.  SOUTH OF A
SMALL MID-LEVEL RIDGE...MICHAEL SHOULD CONTINUE ON A SLOW WESTWARD
TO WEST-NORTHWESTWARD COURSE FOR THE NEXT 24 HOURS.  THE CYCLONE
SHOULD REACH THE WESTERN PERIPHERY OF THIS RIDGE AROUND THAT TIME
AND TURN NORTHWESTWARD. A TURN TOWARD THE NORTH AND THEN
NORTH-NORTHEAST WITH A SIGNIFICANT INCREASE IN FORWARD SPEED IS
EXPECTED IN 36-72 HOURS...AS THE SAME SHORTWAVE TROUGH CAUSING
LESLIE TO RECURVE APPROACHES MICHAEL.  THE NHC TRACK FORECAST HAS
AGAIN BEEN ADJUSTED A BIT TO THE LEFT THROUGH 48 HOURS...FOLLOWING
THE MULTI-MODEL CONSENSUS...AND TO THE RIGHT AT 72 HOURS IN BEST
AGREEMENT WITH THE GFS MODEL.

MICHAEL SHOULD LEAVE THE LOW-SHEAR ENVIRONMENT SOUTH OF THE
AFOREMENTIONED RIDGE AND BEGIN TO FEEL THE EFFECTS OF MODERATE TO
STRONG NORTH-NORTHEASTERLY SHEAR ASSOCIATED WITH THE OUTFLOW OF
LESLIE.  SINCE THE SHEAR IS FORECAST TO BE ONLY OVER A NARROW LAYER
IN THE UPPER TROPOSPHERE...AND MICHAEL WILL BE MOVING OVER ONLY
GRADUALLY DECREASING SEA SURFACE TEMPERATURES...ONLY SLOW WEAKENING
IS FORECAST DURING THE NEXT DAY OR SO.  FASTER WEAKENING IS FORECAST
BY 48 HOURS HOURS ONCE MICHAEL ENCOUNTERS A SUBSTANTIAL INCREASE IN
SOUTH-SOUTHWESTERLY SHEAR ASSOCIATED WITH A STRONG SHORTWAVE TROUGH
CROSSING THE CANADIAN MARITIMES. THE NHC INTENSITY FORECAST IS
REDUCED SLIGHTLY FROM THE PREVIOUS ONE AND IS EXCELLENT AGREEMENT
WITH THE LATEST SHIPS AND INTENSITY CONSENSUS AIDS.
 
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  09/2100Z 33.6N  43.8W   80 KT  90 MPH
 12H  10/0600Z 33.6N  44.9W   75 KT  85 MPH
 24H  10/1800Z 34.2N  46.6W   70 KT  80 MPH
 36H  11/0600Z 36.4N  47.8W   65 KT  75 MPH
 48H  11/1800Z 39.9N  47.5W   50 KT  60 MPH
 72H  12/1800Z 47.2N  40.9W   40 KT  45 MPH...POST-TROP/EXTRATROP
 96H  13/1800Z...DISSIPATED
 
$$
FORECASTER KIMBERLAIN