000
WTNT42 KNHC 020252
TCDAT2
 
TROPICAL STORM PHILIPPE DISCUSSION NUMBER  32
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL172011
1100 PM AST SAT OCT 01 2011
 
PHILIPPE CONTINUES TO INTENSIFY IN SPITE OF MORE THAN 30 KT OF
NORTHERLY SHEAR AFFECTING THE CYCLONE. DATA FROM AN ASCAT PASS
AROUND 0045 UTC SHOWED A MAXIMUM WIND OF 58 KT NORTHEAST OF THE
CENTER...AND THE INITIAL INTENSITY IS SET AT 60 KT FOR THIS
ADVISORY. THE SHIPS MODEL SHOWS THE SHEAR INCREASING EVEN MORE OVER
THE NEXT 12 HOURS...WHICH SHOULD RESULT IN AT LEAST A LITTLE
WEAKENING AS SHOWN BY ALL OF THE GUIDANCE IN THE SHORT TERM. AFTER
THAT TIME...THE SHIPS MODEL SHOWS THE SHEAR GRADUALLY
DECREASING...AND FALLING BELOW 20 KT AS PHILIPPE MOVES UNDER A
SMALL UPPER-LEVEL RIDGE AXIS IN AROUND 3 DAYS. THIS SHOULD ALLOW
THE CYCLONE TO MAINTAIN ITS INTENSITY AFTER 36 HOURS AND
RE-STRENGTHEN A LITTLE IN 3 OR 4 DAYS. THE NEW NHC INTENSITY
FORECAST IS CLOSE TO A BLEND OF THE SHIPS AND LGEM THROUGH THE
PERIOD.
 
THE CENTER OF PHILIPPE HAS BEEN SOMEWHAT DIFFICULT TO LOCATE THIS
EVENING...BUT BASED ON SATELLITE FIXES THE INITIAL MOTION ESTIMATE
IS 290/08. THE TRACK FORECAST REASONING HAS NOT CHANGED...AS
PHILIPPE WILL GRADUALLY TURN TOWARD THE WEST OR EVEN SOUTH OF DUE
WEST DURING THE NEXT COUPLE OF DAYS AS THE RIDGE NORTH OF THE
CYCLONE BUILDS SOUTHWESTWARD AHEAD OF PHILIPPE. BY DAY 3...THE
LARGE TROUGH MOVING OFF THE EAST COAST OF NORTH AMERICA WILL WEAKEN
THE RIDGE AND ALLOW PHILIPPE TO TURN NORTHWARD AND THEN
NORTHEASTWARD BY DAY 5. HOWEVER...THERE IS SIGNIFICANT SPREAD IN
THE GUIDANCE IN THE DETAILS OF THIS TURN. FOR EXAMPLE...AT DAY 5
THE DISTANCE BETWEEN THE FORECAST POSITIONS OF THE SLOWER GFS AND
THE FASTER ECMWF IS MORE THAN 550 NM. THE LATEST RUN OF THE GFS HAS
TRENDED EVEN SLOWER AND FARTHER AWAY FROM THE REST OF THE
GUIDANCE...AS IT IS A BIT WEAKER AND SLOWER MOVING WITH THE TROUGH
INTO THE WESTERN ATLANTIC. GIVEN THE LARGE AND APPARENTLY
INCREASING UNCERTAINTY...LITTLE CHANGE WAS MADE TO THE NHC TRACK
FORECAST. THE NEW TRACK IS A LITTLE TO THE RIGHT OF THE PREVIOUS
ONE AND WAS ADJUSTED TOWARD A BLEND OF THE GFS...ECMWF...GFDL...AND
HWRF MODELS THROUGH THE PERIOD. AT THE END OF THE PERIOD THE
FORWARD MOTION IS SLOWER THAN THE PREVIOUS FORECAST DUE TO THE
LARGE SPREAD IN THE GUIDANCE.

THE 34-KT AND 50-KT RADII IN THE EAST SEMICIRCLE WERE ADJUSTED BASED
ON DATA FROM THE ASCAT PASS. 
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  02/0300Z 25.4N  49.8W   60 KT  70 MPH
 12H  02/1200Z 25.8N  51.3W   55 KT  65 MPH
 24H  03/0000Z 26.0N  53.4W   50 KT  60 MPH
 36H  03/1200Z 25.9N  55.6W   45 KT  50 MPH
 48H  04/0000Z 25.8N  57.8W   45 KT  50 MPH
 72H  05/0000Z 26.5N  61.0W   45 KT  50 MPH
 96H  06/0000Z 28.0N  61.0W   50 KT  60 MPH
120H  07/0000Z 31.5N  57.0W   55 KT  65 MPH
 
$$
FORECASTER BRENNAN