000
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