WTPQ31 RJTD 200000
RSMC TROPICAL CYCLONE PROGNOSTIC REASONING
REASONING NO.13 FOR STS 2518 RAGASA (2518)
1.GENERAL COMMENTS
  STS RAGASA IS LOCATED AT 16.7N, 129.6E. INFORMATION ON THE CURRENT
  POSITION IS BASED ON ANIMATED MSI AND SURFACE OBSERVATIONS.
  POSITIONAL ACCURACY IS FAIR. CENTRAL PRESSURE IS 985HPA AND
  MAXIMUM SUSTAINED WINDS NEAR THE CENTER ARE 55KNOTS. THE SYSTEM IS
  IN A FAVORABLE ENVIRONMENT FOR DEVELOPMENT UNDER THE INFLUENCE OF
  HIGH SSTS, HIGH TCHP, WEAK VWS AND GOOD UPPER-LEVEL OUTFLOW.
  HOWEVER, THE LIMITED FIRMNESS OF ITS STRUCTURE HAS CAUSED IT TO
  MAINTAIN ITS INTENSITY OVER THE LAST SIX HOURS. INFORMATION ON THE
  CURRENT INTENSITY IS BASED ON 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 THE SYSTEM HAS A BAND WITH A CURVATURE SUGGESTING THE
  CSC. ANIMATED MSI SHOWS THE CLOUD CHARACTERISTICS OF ANTICYCLONIC
  OUTFLOW ARE NOW DISTINCT. WATER VAPOR IMAGERY SHOWS DRY AIR AROUND
  THE SYSTEM. DMSP-F18/SSMIS 89 GHZ MICROWAVE IMAGERY SHOWS THE
  SYSTEM HAS A BAND WITH CURVATURE INDICATING THE CSC.
3.TRACK FORECAST
  THE SYSTEM WILL MOVE NORTHWESTWARD DUE TO INTERACTION WITH AN
  UPPER VORTEX UNTIL FT24. THE SYSTEM WILL THEN MOVE
  WEST-NORTHWESTWARD ALONG THE PERIPHERY OF A MID-LEVEL SUB-TROPICAL
  HIGH UNTIL FT96. THE SYSTEM WILL THEN MOVE WESTWARD ALONG THE
  PERIPHERY OF A MID-LEVEL SUB-TROPICAL HIGH 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 FT72 DUE TO THE INFLUENCE OF
  INTERACTION WITH HIGH SSTS, HIGH TCHP, WEAK VWS AND GOOD
  UPPER-LEVEL OUTFLOW. THE SYSTEM WILL THEN MAINTAIN ITS INTENSITY
  UNTIL FT96 DUE TO THE INSUFFICIENT ENVIRONMENT FOR ITS FURTHER
  DEVELOPMENT DESPITE A FAVORABLE ENVIRONMENT UNDER THE INFLUENCE OF
  INTERACTION WITH HIGH SSTS, HIGH TCHP, WEAK VWS AND GOOD
  UPPER-LEVEL OUTFLOW. THE SYSTEM WILL THEN WEAKEN UNTIL FT120 DUE
  TO THE INFLUENCE OF INTERACTION WITH REDUCED TCHP AND LAND. THE
  INTENSITY FORECAST IS BASED ON A CONSENSUS OF GUIDANCE DATA
  INCLUDING GSM.
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