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#463950 (Received by flhurricane at: 10:38 PM 03.Oct.2011) TCDAT2 TROPICAL STORM PHILIPPE DISCUSSION NUMBER 40 NWS NATIONAL HURRICANE CENTER MIAMI FL AL172011 1100 PM AST MON OCT 03 2011 PHILIPPE SEEMS TO BE HOLDING ITS OWN. WHILE CLOUD TOP TEMPERATURES HAVE RECENTLY WARMED NEAR THE CENTER...THE CYCLONE HAS BEEN MAINTAINING A FAIRLY STABLE CONVECTIVE PATTERN FOR SOME TIME. THE PERSISTENCE OF THE CONVECTION SUGGESTS THAT THE UPPER-LEVEL SHEAR AFFECTING THE STORM HAS GRADUALLY WEAKENED. A LATE AFTERNOON MICROWAVE OVERPASS ALSO INDICATED A LOW- TO MID-LEVEL EYE FEATURE EMBEDDED WITHIN THE MAIN CLOUD MASS...WITH A CONSIDERABLE DECREASE IN THE TILT OF THE VORTEX SINCE EARLIER TODAY. OVERALL...THE SATELLITE APPEARANCE OF THE STORM HAS NOT CHANGED MUCH...AND AN AVERAGE OF 0000 UTC DVORAK T- AND CI-NUMBERS RESULTS IN HOLDING THE INITIAL INTENSITY AT 55 KT. PHILIPPE HAD BEEN MOVING SOUTHWESTWARD THROUGHOUT THE DAY...BUT LATEST FIXES SUGGEST A MOTION OF 240/10 KT. THE CYCLONE IS FORECAST TO CONTINUE ON A WEST-SOUTHWESTWARD AND THEN WESTWARD COURSE FOR THE NEXT DAY OR SO...EQUATORWARD OF A MID-LEVEL RIDGE ORIENTED NORTHEAST TO SOUTHWEST OVER THE CENTRAL ATLANTIC. BY 36 HOURS...THE RIDGE WILL SHIFT EASTWARD AND WEAKEN AS A COMPLEX AND AMPLIFIED TROUGH CURRENTLY OVER THE EASTERN UNITED STATES MOVES INTO THE WESTERN ATLANTIC. THIS PATTERN SHOULD CAUSE PHILIPPE TO TURN NORTHWARD AND SLOW BEFORE THE CYCLONE REACHES THE DEEP-LAYER WESTERLIES...WHICH SHOULD RESULT IN RECURVATURE BY 72 HOURS. THE MODEL GUIDANCE HAS SHIFTED TOWARD THE EAST THIS CYCLE AND IS NOW FORECASTING A SHARPER RECURVATURE...WITH CONSIDERABLE SPREAD NOTED AT 24 TO 48 HOURS. THE OFFICIAL NHC TRACK FORECAST HAS BEEN ADJUSTED SOUTHWARD DUE TO THE RECENT CENTER RE-LOCATION AND CONTINUES TO FAVOR THE MORE SOUTHERLY MODEL SOLUTIONS...GIVEN THEIR BETTER HANDLE ON THE BOTH THE PREVIOUS AND CURRENT MOTION. AN ALTERNATIVE SCENARIO DEPICTED BY SOME MODELS IS FOR PHILIPPE TO BECOME ABSORBED BY AN ADVANCING FRONTAL TROUGH BETWEEN 72 AND 120 HOURS. THE INTENSITY FORECAST REMAINS RATHER TRICKY. THE MODELS SUGGEST A FURTHER REDUCTION IN SHEAR AFTER ABOUT 24 HOURS...WITH A RELATIVE MINIMUM IN SHEAR OCCURRING IN ABOUT 36 TO 72 HOURS. THIS MORE FAVORABLE UPPER-AIR PATTERN SUGGESTS THAT SOME INTENSIFICATION IS POSSIBLE...AND PHILIPPE IS FORECAST TO REACH HURRICANE STRENGTH DURING THIS TIME PERIOD. AFTER 72 HOURS...INCREASING WEST- SOUTHWESTERLY SHEAR AND MUCH DRIER AIR SURGING SOUTHEASTWARD BEHIND A FRONTAL ZONE IMPINGING UPON PHILIPPE SHOULD LEAD TO WEAKENING... PERHAPS EVEN FASTER THAN INDICATED HERE. THE NEW NHC INTENSITY FORECAST IS A BIT HIGHER THAN THE PREVIOUS ONE...BUT NEAR THE MULTI-MODEL CONSENSUS THROUGH 72 HOURS. BEYOND THAT TIME...THE FORECAST IS REDUCED FROM THE LAST ADVISORY AND IS BELOW THE INTENSITY GUIDANCE GIVEN THE INCREASINGLY UNFAVORABLE ENVIRONMENT FORECAST OVER PHILIPPE. FORECAST POSITIONS AND MAX WINDS INIT 04/0300Z 23.7N 57.1W 55 KT 65 MPH 12H 04/1200Z 23.5N 58.5W 55 KT 65 MPH 24H 05/0000Z 23.9N 60.3W 60 KT 70 MPH 36H 05/1200Z 24.5N 61.2W 60 KT 70 MPH 48H 06/0000Z 25.3N 61.6W 65 KT 75 MPH 72H 07/0000Z 27.0N 60.5W 65 KT 75 MPH 96H 08/0000Z 28.7N 56.4W 55 KT 65 MPH 120H 09/0000Z 30.3N 52.6W 50 KT 60 MPH $$ FORECASTER KIMBERLAIN |