WTPQ31 RJTD 261200
RSMC TROPICAL CYCLONE PROGNOSTIC REASONING
REASONING NO. 1 FOR TD LOCATED AT 9.3N 140.9E
1.GENERAL COMMENTS
A TD IS LOCATED AT 9.3N, 140.9E. INFORMATION ON THE CURRENT
POSITION IS BASED ON ANIMATED MSI AND SURFACE OBSERVATIONS.
POSITIONAL ACCURACY IS POOR BECAUSE THE CSC IS OBSCURE. CENTRAL
PRESSURE IS 1006HPA AND MAXIMUM SUSTAINED WINDS NEAR THE CENTER
ARE 30KNOTS. THE SYSTEM IS IN A FAVORABLE ENVIRONMENT FOR
DEVELOPMENT UNDER THE INFLUENCE OF HIGH SSTS, HIGH TCHP, WEAK VWS
AND GOOD UPPER-LEVEL OUTFLOW. THIS HAS CAUSED THE SYSTEM TO
DEVELOP OVER THE LAST SIX HOURS. INFORMATION ON THE CURRENT
INTENSITY IS BASED ON EARLY STAGE DVORAK INTENSITY ANALYSES AND
SURFACE OBSERVATIONS.
2.SYNOPTIC SITUATION
THE SYSTEM IS MOVING SLOWLY WEST-NORTHWESTWARD ALONG THE
SOUTHWESTERN PERIPHERY OF A MID-LEVEL SUB-TROPICAL HIGH. ANIMATED
MSI SHOWS CB CLUSTERS GATHERING AROUND THE CSC AND STARTING TO
FORM A CURVED BAND. WATER VAPOR IMAGERY SHOWS DRY AIR AROUND THE
SYSTEM. GPM/GMI 89 GHZ MICROWAVE IMAGERY SHOWS THE SYSTEM HAS
ACTIVE CONVECTIVE CLOUD CLUSTERS AROUND THE CSC.
3.TRACK FORECAST
THE SYSTEM WILL MOVE NORTH-NORTHWESTWARD ALONG THE PERIPHERY OF A
MID-LEVEL SUB-TROPICAL HIGH UNTIL FT96. THE SYSTEM WILL THEN MOVE
NORTHWESTWARD UNTIL FT120. THE TRACK FORECAST IS BASED ON GSM
PREDICTIONS, AND REFERENCE TO OTHER NWP MODELS. TRACK FORECAST
CONFIDENCE IS FAIR BECAUSE ALL NWP MODELS ARE IN CLOSE AGREEMENT.
4.INTENSITY FORECAST
THE SYSTEM WILL DEVELOP UNTIL FT120 DUE TO THE INFLUENCE OF
INTERACTION WITH HIGH SSTS, HIGH TCHP, WEAK VWS AND GOOD UPPER
LEVEL OUTFLOW. THE SYSTEM WILL BE UPGRADED TO TS INTENSITY BY
FT24. THE INTENSITY FORECAST IS BASED ON A CONSENSUS OF GUIDANCE
DATA INCLUDING GSM.
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