282 
 WTNT42 KNHC 200830
 TCDAT2
 HURRICANE PHILIPPE DISCUSSION NUMBER  12
 NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
 5 AM EDT TUE SEP 20 2005
 
 PHILIPPE'S CLOUD PATTERN IS CHARACTERIZED BY A RATHER AMORPHOUS-
 LOOKING MASS OF VERY DEEP CONVECTION...ALTHOUGH RECENT SATELLITE
 IMAGES SUGGEST THAT IT MAY BE DEVELOPING SORT OF A COMMA SHAPE. 
 THE LACK OF UPPER-LEVEL OUTFLOW OVER THE WESTERN SECTORS OF THE
 HURRICANE SUGGESTS SOME WESTERLY SHEARING...DUE TO THE FLOW AT THE
 BASE OF A BROAD UPPER-TROPOSPHERIC TROUGH ASSOCIATED WITH THE
 OUTFLOW TO THE EAST OF RITA.  ALTHOUGH THE SHIPS MODEL ALSO
 DIAGNOSES SIGNIFICANT SHEAR AFFECTING PHILIPPE DURING THE FORECAST
 PERIOD...IT NONETHELESS PREDICTS SOME STRENGTHENING.  THE OFFFICIAL
 FORECAST SIMILARLY SHOWS AN INCREASE IN STRENGTH UP TO 48
 HOURS...BUT GOES A FAIR AMOUNT BELOW SHIPS THEREAFTER BECAUSE THE
 SHEAR IS EXPECTED TO BECOME SIMPLY TOO STRONG FOR PHILIPPE TO
 MAINTAIN ITS INTENSITY BY THAT TIME.
 
 I HAVE ESTIMATED THE CENTER TO BE WEST OF THE FIXES FROM THE VARIOUS 
 AGENCIES...BOTH FOR CONTINUITY FROM THE PREVIOUS TRACK...AND THE
 PRESENCE OF WESTERLY SHEAR.  TRACK FORECAST PHILOSPHY REMAINS
 ESSENTIALLY UNCHANGED FROM THE PAST FEW ADVISORY PACKAGES. 
 PHILIPPE IS MOVING TOWARD A BREAK IN THE SUBTROPICAL RIDGE IN THE
 VICINITY OF 60W.  LATE IN THE FORECAST PERIOD...A STRONG 500 MB
 SHORTWAVE TROUGH IS EXPECTED TO DIG SOUTHWARD FROM THE CANADIAN
 MARITIMES.  THIS FEATURE SHOULD CAUSE PHILIPPE TO ACCELERATE
 NORTHEASTWARD BY DAYS 4-5.  THE OFFICIAL TRACK FORECAST IS QUITE
 SIMILAR TO THE PREVIOUS ONE...AND ALONG THE GENERAL TRAJECTORY
 OF...BUT A LITTLE SLOWER THAN...THE DYNAMICAL MODEL CONSENSUS.
 
 FORECASTER PASCH
  
  
 FORECAST POSITIONS AND MAX WINDS
  
 INITIAL      20/0900Z 18.8N  56.8W    70 KT
  12HR VT     20/1800Z 19.8N  57.2W    70 KT
  24HR VT     21/0600Z 21.3N  57.6W    75 KT
  36HR VT     21/1800Z 23.0N  58.1W    80 KT
  48HR VT     22/0600Z 25.0N  58.6W    85 KT
  72HR VT     23/0600Z 29.5N  59.5W    75 KT
  96HR VT     24/0600Z 34.0N  58.0W    65 KT
 120HR VT     25/0600Z 38.0N  52.0W    60 KT
  
  
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