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Tropical Storm PHILIPPE (Text)

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TROPICAL STORM PHILIPPE DISCUSSION NUMBER  25...CORRECTED
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL172011
500 AM AST FRI SEP 30 2011
 
CORRECTED INITIAL MOTION

THE RECENT EVOLUTION OF PHILIPPE IS A BIT OF A MYSTERY. A COUPLE OF
RECENT MICROWAVE OVERPASSES INDICATE THAT PHILIPPE HAS A WELL-
DEFINED EYE FEATURE IN THE LOW LEVELS...SUGGESTING THAT THERE HAS
BEEN A NET INCREASE IN THE STRUCTURAL ORGANIZATION OF THE CYCLONE
DURING THE LAST 24 HOURS. HOWEVER...GEOSTATIONARY SATELLITE IMAGES
INDICATE THAT THE CONVECTIVE PATTERN OF THE STORM IS SOMEWHAT
CHAOTIC...WITH THE MAIN CLUSTER OF DEEP CONVECTION WELL TO THE
NORTHEAST OF THE CENTER UNTIL RECENTLY.  GIVEN THAT THERE HAS BEEN
NO APPRECIABLE CHANGE IN THE OVERALL ORGANIZATION SINCE THE LAST
ADVISORY...THE INITIAL WIND SPEED ESTIMATE IS HELD AT 40 KT.
 
ALTHOUGH THERE HAS BEEN A RELATIVE RELAXATION OF THE SHEAR DURING
THE LAST 12-24 HOURS...PHILIPPE HAS NOT STRENGTHENED YET. HOWEVER...
THE BETTER ORGANIZED LOW-LEVEL STRUCTURE OF THE STORM WOULD SEEM TO
BE CONDUCIVE FOR SOME INCREASE IN STRENGTH WHILE THE SHEAR REMAINS
LOW. WITHIN 24-36 HOURS...WEAKENING SEEMS LIKELY AS PHILIPPE SHOULD
ENTER A REGION DOMINATED BY THE VERY STRONG UPPER-LEVEL
NORTHWESTERLY WINDS ASSOCIATED WITH THE OUTFLOW OF OPHELIA.
ASSUMING THAT PHILIPPE CAN WITHSTAND WIND SHEAR OF THAT
MAGNITUDE...THERE COULD BE AN OPPORTUNITY FOR SOME INTENSIFICATION
TOWARD THE END OF THE FORECAST PERIOD.  THE NEW NHC INTENSITY
FORECAST IS UNCHANGED FROM THE PREVIOUS ONE IN THE SHORT TERM BUT A
BIT LOWER AFTER 36 HOURS...JUST BELOW THE STATISTICAL-DYNAMICAL
GUIDANCE.
 
PHILIPPE APPEARS TO BE MOVING NORTHWESTWARD OR 315 DEGREES AT 11
KT...BUT THE LACK OF CONFIDENCE IN EARLIER CENTER FIXES MAKES THIS
ESTIMATE SOMEWHAT UNCERTAIN.  GLOBAL MODELS SHOW PHILIPPE BEING
STEERED WEST-NORTHWESTWARD TO NORTHWESTWARD DURING THE NEXT DAY OR
SO ON THE SOUTHWESTERN PERIPHERY OF A MID-LEVEL HIGH OVER THE
EASTERN TROPICAL ATLANTIC.  AFTER THAT...AN AMPLIFYING MID- TO
UPPER-LEVEL TROUGH OVER THE EASTERN UNITED STATES SHOULD CAUSE
HEIGHTS TO RISE OVER THE CENTRAL ATLANTIC WHICH...IN TURN...SHOULD
RESULT IN PHILIPPE'S TURNING WESTWARD.  THE NEW NHC TRACK IS
BASICALLY AN UPDATE OF THE PREVIOUS FORECAST AND CONTINUES TO
FAVOR THE ECMWF SOLUTION ON THE SOUTHERN SIDE OF THE GUIDANCE
ENVELOPE WHICH HAS A WEAKER VERSION OF PHILIPPE.  THE OFFICIAL
FORECAST IS WELL TO THE LEFT OF MULTI-MODEL CONSENSUS AT LATER
TIMES SINCE MOST OF THE MODELS ASSUME A STRONGER CYCLONE.
  
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  30/0900Z 21.9N  44.9W   40 KT  45 MPH
 12H  30/1800Z 22.9N  46.2W   45 KT  50 MPH
 24H  01/0600Z 23.9N  47.9W   45 KT  50 MPH
 36H  01/1800Z 24.5N  49.8W   40 KT  45 MPH
 48H  02/0600Z 24.9N  51.6W   35 KT  40 MPH
 72H  03/0600Z 25.1N  55.4W   30 KT  35 MPH
 96H  04/0600Z 25.0N  58.8W   30 KT  35 MPH
120H  05/0600Z 24.5N  62.0W   35 KT  40 MPH
 
$$
FORECASTER KIMBERLAIN
 
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