Hurricane MICHAEL

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HURRICANE MICHAEL DISCUSSION NUMBER  30
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL132012
1100 AM AST MON SEP 10 2012
 
THE SATELLITE PRESENTATION OF MICHAEL HAS NOT CHANGED MUCH IN
ORGANIZATION SINCE THE LAST ADVISORY.  WHILE THE EYE HAS CLEARED
AND BECOME SOMEWHAT BETTER DEFINED...CLOUD TOP TEMPERATURES HAVE
NOT COOLED APPRECIABLY.  THE CLOUD PATTERN HAS RECENTLY BECOME MORE
SYMMETRIC...BUT THERE IS STILL EVIDENCE OF NORTHERLY SHEAR OVER THE
CYCLONE.  SINCE DVORAK T-NUMBERS FROM TAFB/SAB ARE UNCHANGED SINCE
0600 UTC...THE INITIAL INTENSITY ESTIMATE IS HELD AT 70 KT. 
WEAKENING SHOULD BEGIN IN EARNEST AS MICHAEL ENCOUNTERS INCREASING
NORTH-NORTHEASTERLY SHEAR AND SLOWLY DECREASING SEA SURFACE
TEMPERATURES DURING THE NEXT 24-36 HOURS. AFTER THAT...EVEN
COOLER WATERS AND STRONG SOUTH-SOUTHWESTERLY SHEAR SHOULD HASTEN
THE TRANSITION OF MICHAEL TO AN EXTRATROPICAL CYCLONE IN ABOUT 48
HOURS.  THE NHC INTENSITY FORECAST IS JUST A BIT LOWER THAN THE
PREVIOUS ONE...IN GOOD AGREEMENT WITH THE LATEST SHIPS OUTPUT AS
WELL AS THE INTENSITY CONSENSUS AIDS.
 
MICHAEL HAS BEEN MOVING SLIGHTLY FASTER TOWARD THE WEST...THOUGH
RECENT CENTER FIXES SUGGEST A MOTION TO THE RIGHT OF THAT HEADING
NOW. THE INITIAL MOTION ESTIMATE...REPRESENTING A LONGER-TERM
AVERAGE OF CENTER FIXES...IS 270/07.  THE CYCLONE SHOULD BE STEERED
WEST-NORTHWESTWARD AND THEN NORTHWESTWARD DURING THE NEXT 12-18
HOURS AROUND THE SOUTHWESTERN PERIPHERY OF A MID-LEVEL RIDGE NEAR
38N 46W.  BEYOND THIS TIME...A TURN TOWARD THE NORTH AND THEN
NORTH-NORTHEAST WITH SIGNIFICANT ACCELERATION IS EXPECTED.  THIS
SHOULD OCCUR AS MICHAEL BECOMES EMBEDDED IN THE FLOW BETWEEN THE
RIDGE TO ITS EAST AND A POTENT SHORTWAVE TROUGH MOVING THROUGH THE
CANADIAN MARITIMES.  WITH THE TRACK GUIDANCE IN RELATIVELY GOOD
AGREEMENT...NO SIGNIFICANT CHANGES WERE MADE TO THE PREVIOUS
FORECAST TRACK.
 
  
FORECAST POSITIONS AND MAX WINDS
 
INIT  10/1500Z 33.6N  46.3W   70 KT  80 MPH
 12H  11/0000Z 34.8N  47.6W   60 KT  70 MPH
 24H  11/1200Z 37.5N  48.1W   50 KT  60 MPH
 36H  12/0000Z 41.2N  46.7W   45 KT  50 MPH
 48H  12/1200Z 45.9N  42.8W   40 KT  45 MPH...POST-TROP/EXTRATROP
 72H  13/1200Z 54.0N  28.0W   40 KT  45 MPH...POST-TROP/EXTRATROP
 96H  14/1200Z...ABSORBED BY FRONT
 
$$
FORECASTER KIMBERLAIN
 
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