Tropical Storm PHILIPPE
ZCZC MIATCDAT2 ALL TTAA00 KNHC DDHHMM TROPICAL STORM PHILIPPE DISCUSSION NUMBER 20 NWS NATIONAL HURRICANE CENTER MIAMI FL AL172011 1100 PM AST WED SEP 28 2011 PHILIPPE REMAINS A SHEARED TROPICAL CYCLONE...HOWEVER DEEP CONVECTION HAS DEVELOPED AND PERSISTED CLOSER TO THE LOW-LEVEL CENTER DURING THE PAST SEVERAL HOURS. SATELLITE ESTIMATES FROM TAFB AND SAB SUPPORT AN INTENSITY OF 40 KT...AND THIS COULD BE A LITTLE CONSERVATIVE. THE UPPER-WIND PATTERN AHEAD OF PHILIPPE APPEARS TO BE A LITTLE MORE CONDUCIVE FOR STRENGTHENING DURING THE NEXT DAY OR SO. AN UPPER-LEVEL TROUGH TO THE WEST OF THE CYCLONE IS FORECAST TO CUT-OFF AND MOVE SOUTHWESTWARD. THIS SHOULD RESULT IN A REDUCTION OF THE SHEAR AND THE UPDATED NHC INTENSITY FORECAST NOW CALLS FOR SOME MODEST INCREASE IN INTENSITY DURING THE NEXT 24-36 HOURS. THIS IS IN GOOD AGREEMENT WITH THE SHIPS/LGEM GUIDANCE. IN 2 TO 3 DAYS PHILIPPE IS FORECAST TO MOVE NEAR THE EASTERN SIDE OF AN UPPER-LEVEL RIDGE...IN AN AREA OF STRONG NORTHERLY WINDS ASSOCIATED WITH THE OUTFLOW FROM OPHELIA. THIS SHOULD CAUSE PHILIPPE TO QUICKLY WEAKEN AND BECOME A REMNANT LOW IN ABOUT 4 DAYS. THE TRACK FORECAST REASONING REMAINS UNCHANGED AND THE GUIDANCE REMAINS IN FAIRLY GOOD AGREEMENT DURING THE FIRST 2-3 DAYS. PHILIPPE SHOULD CONTINUE ON A WEST-NORTHWEST TO NORTHWEST MOTION AROUND THE SOUTHWESTERN PERIPHERY OF A MID-LEVEL RIDGE OVER THE EASTERN ATLANTIC. AFTER 72 HOURS...THE CYCLONE IS FORECAST TO TURN WESTWARD AS A STRONG DEEP-LAYER RIDGE BUILDS OVER THE NORTH-CENTRAL ATLANTIC. THE OFFICIAL FORECAST HAS BEEN ADJUSTED A LITTLE WESTWARD DURING THE FIRST 72 HOURS...AND IS A LITTLE SOUTH OF THE PREVIOUS TRACK THEREAFTER. THE NHC TRACK IS NEAR THE MIDDLE OF THE GUIDANCE ENVELOPE. FORECAST POSITIONS AND MAX WINDS INIT 29/0300Z 17.4N 40.8W 40 KT 45 MPH 12H 29/1200Z 18.3N 42.1W 45 KT 50 MPH 24H 30/0000Z 19.8N 43.8W 50 KT 60 MPH 36H 30/1200Z 21.2N 45.6W 50 KT 60 MPH 48H 01/0000Z 22.2N 47.3W 45 KT 50 MPH 72H 02/0000Z 23.8N 50.9W 35 KT 40 MPH 96H 03/0000Z 24.5N 55.0W 30 KT 35 MPH...POST-TROP/REMNT LOW 120H 04/0000Z 24.5N 59.0W 30 KT 35 MPH...POST-TROP/REMNT LOW $$ FORECASTER BROWN NNNN