763 
 WTNT42 KNHC 081454
 TCDAT2
  
 TROPICAL STORM PHILIPPE DISCUSSION NUMBER  58
 NWS NATIONAL HURRICANE CENTER MIAMI FL       AL172011
 1100 AM AST SAT OCT 08 2011
  
 MICROWAVE SATELLITE FIXES AND REPORTS FROM DRIFTING BUOY 41575
 INDICATE THE CENTER OF PHILIPPE IS A LITTLE NORTH OF THE PREVIOUS
 ADVISORY POSITION. OTHERWISE...THE CYCLONE IS ON TRACK AND IS
 ACCELERATING TOWARD THE NORTHEAST...OR 050/25 KT. THERE IS NO
 SIGNIFICANT CHANGE TO PREVIOUS FORECAST TRACK OR REASONING.
 PHILIPPE IS EMBEDDED IN DEEP-LAYER SOUTHWESTERLY FLOW AHEAD OF A
 SHARP UPPER-LEVEL TROUGH AND FRONTAL SYSTEM THAT EXTENDS FROM
 NEWFOUNDLAND SOUTHWARD INTO THE CENTRAL ATLANTIC. THE FLOW AHEAD 
 OF THE TROUGH IS FORECAST TO INCREASE AND BACK AROUND TO A
 SOUTH-SOUTHWESTERLY DIRECTION...WHICH SHOULD ACT TO ACCELERATE
 PHILIPPE NORTH-NORTHEASTWARD OVER COLD WATERS THAT LIE JUST NORTH
 OF 37N LATITUDE. THE OFFICIAL FORECAST TRACK IS JUST AN UPDATE OF
 THE PREVIOUS TRACK AND LIES CLOSE TO THE NHC CONSENSUS MODELS TVCN
 AND TVCA.
 
 SOUTHWESTERLY VERTICAL WIND SHEAR OF MORE THAN 40 KT...COUPLED WITH
 SSTS BELOW 24C...IS EXPECTED TO INDUCE EXTRATROPICAL TRANSITION
 BETWEEN 12 AND 24 HOURS. PHILIPPE COULD ALSO MERGE WITH AN
 APPROACHING FRONTAL SYSTEM DURING THAT SAME TIME PERIOD. THE BOTTOM
 LINE IS THAT PHILIPPE SHOULD SLOWLY WEAKEN THROUGHOUT THE FORECAST
 PERIOD AND BE FULLY POST-TROPICAL/EXTRATROPICAL BY 24 HOURS OVER
 THE FAR NORTH ATLANTIC. THE INTENSITY FORECAST IS A BLEND OF THE
 SHIPS/LGEM INTENSITY MODELS AND GUIDANCE FROM THE NOAA OCEAN
 PREDICTION CENTER. WIND RADII ARE BASED ON INPUT FROM THE OCEAN
 PREDICTION CENTER.
  
 FORECAST POSITIONS AND MAX WINDS
  
 INIT  08/1500Z 33.2N  47.9W   50 KT  60 MPH
  12H  09/0000Z 35.7N  45.6W   45 KT  50 MPH
  24H  09/1200Z 39.1N  42.4W   45 KT  50 MPH...POST-TROP/EXTRATROP
  36H  10/0000Z 42.5N  39.5W   45 KT  50 MPH...POST-TROP/EXTRATROP
  48H  10/1200Z 46.3N  36.5W   45 KT  50 MPH...POST-TROP/EXTRATROP
  72H  11/1200Z 54.0N  28.5W   40 KT  45 MPH...POST-TROP/EXTRATROP
  96H  12/1200Z 59.0N  18.5W   35 KT  40 MPH...POST-TROP/EXTRATROP
 120H  13/1200Z...DISSIPATED
  
 $$
 FORECASTER STEWART