WTPQ31 RJTD 121200
RSMC TROPICAL CYCLONE PROGNOSTIC REASONING
REASONING NO. 9 FOR TS 2406 SON-TINH (2406)
1.GENERAL COMMENTS
  TS SON-TINH IS LOCATED AT 32.9N, 150.5E. INFORMATION ON THE
  CURRENT POSITION IS BASED ON ANIMATED MSI AND SURFACE
  OBSERVATIONS. POSITIONAL ACCURACY IS FAIR. CENTRAL PRESSURE IS
  1000HPA AND MAXIMUM SUSTAINED WINDS NEAR THE CENTER ARE 35KNOTS.
  THE SYSTEM IS IN A NEUTRAL ENVIRONMENT FOR DEVELOPMENT UNDER THE
  INFLUENCE OF WEAK VWS, LOW TCHP AND DRY AIR. THIS HAS CAUSED THE
  SYSTEM 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 NORTHWESTWARD ALONG THE SOUTHWESTERN
  PERIPHERY OF A MID-LEVEL SUB-TROPICAL HIGH. ANIMATED MSI SHOWS THE
  SEPARATION OF ACTIVE CONVECTIVE CLOUD CLUSTERS FROM THE CSC.
3.TRACK FORECAST
  THE SYSTEM WILL MOVE NORTHWESTWARD ALONG THE PERIPHERY OF A
  MID-LEVEL SUB-TROPICAL HIGH UNTIL FT24. THE TRACK FORECAST IS
  BASED ON GSM PREDICTIONS, AND REFERENCE TO OTHER NWP MODELS. TRACK
  FORECAST CONFIDENCE IS HIGH BECAUSE ALL NWP MODELS ARE IN CLOSE
  AGREEMENT.
4.INTENSITY FORECAST
  THE SYSTEM WILL GRADUALLY WEAKEN UNTIL FT24 DUE TO THE INFLUENCE
  OF INCREASED VWS. THE SYSTEM WILL WEAKEN TO TD INTENSITY BY FT24.
  THE INTENSITY FORECAST IS BASED ON A CONSENSUS OF GUIDANCE DATA
  INCLUDING GSM.
=