[Tropical] Tropical Cyclone Discussion

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WTNT42 KNHC 040836
TCDAT2

TROPICAL STORM PHILIPPE DISCUSSION NUMBER  41
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL172011
500 AM AST TUE OCT 04 2011

PHILIPPE IS A RARE CREATURE. IT HAS AN EYE FEATURE IN BOTH
CONVENTIONAL AND MICROWAVE SATELLITE DATA BUT DO NOT HAVE ENOUGH
CONVECTION FOR THE SUBJECTIVE DVORAK T-NUMBERS TO INDICATE
HURRICANE STRENGTH. IN FACT...THESE ESTIMATES YIELD TO LOWER WINDS
THAN EARLIER TODAY. ON THE OTHER HAND...THE UW-CIMSS SUGGEST THAT
PHILIPPE IS A HURRICANE. GIVEN SUCH UNCERTAINTY...THE INITIAL
INTENSITY IS KEPT AT 55 KNOTS AT THIS TIME. I WOULD LOVE TO
HAVE A RECONNAISSANCE PLANE TO REALLY KNOW THE TRUE INTENSITY OF
PHILIPPE.

THERE IS AN OPPORTUNITY FOR PHILIPPE TO STRENGTHEN SOME AS THE SHEAR
RELAXES IN THE NEXT COUPLE OF DAYS...AND BEFORE IT BECOMES ATTACHED
TO THE SUBTROPICAL WESTERLY FLOW. THE OFFICIAL FORECAST FOLLOWS THE
GUIDANCE TREND AND MAKES PHILLIPE A HURRICANE IN A DAY OR SO...BUT
THIS FORECAST CONTINUES TO BE HIGHLY UNCERTAIN.

PHILIPPE HAS BEEN MOVING TOWARD THE WEST-SOUTHWEST TRAPPED SOUTH OF
A STRONG SUBTROPICAL RIDGE . IT APPEARS THAT IT HAS NOW BEGUN TO
MOVE TOWARD THE WEST OR 265 DEGREES AT 9 KNOTS AS IT REACHING THE
WESTERN EDGE OF THE RIDGE. A LARGE MID-LATITUDE TROUGH WITH ITS
ASSOCIATED COLD FRONT FRONT IS APPROACHING FROM THE WEST AND THIS
PATTERN WILL FORCE PHILIPPE TO SHARPLY TURN TO THE NORTHEAST OR
RECURVE IN ABOUT 48 HOURS.  PHILIPPE MOST LIKELY WILL BECOME
EMBEDDED IN THE WESTERLIES AND BEGINS TO INTERACT WITH THE COLD
FRONT. THESE TWO FEATURES ARE FORECAST TO BE VERY CLOSE TO EACH
OTHER BY THE GLOBAL MODELS. THERE IS A MEDIUM TO HIGH CONFIDENCE IN
THE SHARP TURN TO THE NORTHEAST SINCE THIS IS THE TREND INDICATED BY
MOST OF THE TRACK GUIDANCE. HOWEVER...SOME OF THE PREVIOUS GFS RUNS
HAVE PHILIPPE MEANDERING JUST SOUTH OF THE COLD FRONT.


FORECAST POSITIONS AND MAX WINDS

INIT  04/0900Z 23.6N  58.3W   55 KT  65 MPH
 12H  04/1800Z 23.5N  59.7W   55 KT  65 MPH
 24H  05/0600Z 23.8N  61.7W   60 KT  70 MPH
 36H  05/1800Z 24.5N  62.0W   65 KT  75 MPH
 48H  06/0600Z 26.0N  62.5W   65 KT  75 MPH
 72H  07/0600Z 27.5N  60.5W   65 KT  75 MPH
 96H  08/0600Z 29.0N  56.0W   55 KT  65 MPH
120H  09/0600Z 32.0N  51.0W   50 KT  60 MPH

$$
FORECASTER AVILA



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