WTPQ32 RJTD 161800
RSMC TROPICAL CYCLONE PROGNOSTIC REASONING
REASONING NO.20 FOR TY 2407 AMPIL (2407)
1.GENERAL COMMENTS
  TY AMPIL IS LOCATED AT 36.0N, 142.6E. INFORMATION ON THE CURRENT
  POSITION IS BASED ON ANIMATED MSI AND SURFACE OBSERVATIONS.
  POSITIONAL ACCURACY IS GOOD. CENTRAL PRESSURE IS 950HPA AND
  MAXIMUM SUSTAINED WINDS NEAR THE CENTER ARE 85KNOTS. THE SYSTEM IS
  IN A FAVORABLE ENVIRONMENT FOR DEVELOPMENT UNDER THE INFLUENCE OF
  HIGH SSTS. HOWEVER, THE INSUFFICIENT ENVIRONMENT FOR ITS FURTHER
  DEVELOPMENT 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 NORTH-NORTHEASTWARD ALONG THE NORTHWESTERN
  PERIPHERY OF A MID-LEVEL SUB-TROPICAL HIGH. ANIMATED MSI SHOWS A
  BAND SPIRALING AROUND THE CSC BY AT LEAST 360 DEGREES. ANIMATED
  MSI SHOWS GOOD CLOUD CHARACTERISTICS OF ANTICYCLONIC OUTFLOW.
3.TRACK FORECAST
  THE SYSTEM WILL MOVE EAST-NORTHEASTWARD ALONG THE PERIPHERY OF A
  MID-LEVEL SUB-TROPICAL HIGH UNTIL FT12. THE SYSTEM WILL THEN
  GRADUALLY ACCELERATE AND MOVE EAST-NORTHEASTWARD UNDER THE
  INFLUENCE OF A MID-LATITUDE TROUGH UNTIL FT48. 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 MAINTAIN ITS INTENSITY UNTIL FT12 DUE TO THE
  INFLUENCE OF INTERACTION WITH HIGH SSTS AND REDUCED TCHP. THE
  SYSTEM WILL THEN WEAKEN UNTIL FT48 DUE TO THE INFLUENCE OF
  INTERACTION WITH LOWER SSTS, INCREASED VWS AND LOW TCHP. THE
  SYSTEM WILL TRANSFORM INTO AN EXTRATROPICAL CYCLONE BY FT48. THE
  INTENSITY FORECAST IS BASED ON A CONSENSUS OF GUIDANCE DATA
  INCLUDING GSM.
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