WTPQ32 RJTD 301800
RSMC TROPICAL CYCLONE PROGNOSTIC REASONING
REASONING NO.28 FOR STS 2509 KROSA (2509)
1.GENERAL COMMENTS
  STS KROSA IS LOCATED AT 29.4N, 143.2E. INFORMATION ON THE CURRENT
  POSITION IS BASED ON ANIMATED MSI AND SURFACE OBSERVATIONS.
  POSITIONAL ACCURACY IS GOOD. CENTRAL PRESSURE IS 980HPA AND
  MAXIMUM SUSTAINED WINDS NEAR THE CENTER ARE 50KNOTS. THE SYSTEM IS
  IN A NEUTRAL ENVIRONMENT FOR DEVELOPMENT UNDER THE INFLUENCE OF
  WEAK VWS AND LOW TCHP. 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 ALMOST STATIONARY BETWEEN TWO MID-LEVEL SUB-TROPICAL
  HIGHS. 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 IN THE DIRECTION OF THE MOVEMENT. GCOM-W/AMSR2 89
  GHZ MICROWAVE IMAGERY SHOWS THE SYSTEM HAS A BAND WITH CURVATURE
  INDICATING THE CSC.
3.TRACK FORECAST
  THE SYSTEM WILL MOVE NORTH-NORTHWESTWARD BETWEEN TWO MID-LEVEL
  SUB-TROPICAL HIGHS UNTIL FT48. THE SYSTEM WILL THEN MOVE
  EAST-NORTHEASTWARD 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
  LOW DUE TO SIGNIFICANT DIFFERENCES AMONG NWP MODEL OUTPUTS.
4.INTENSITY FORECAST
  THE SYSTEM WILL DEVELOP UNTIL FT24 DUE TO THE INFLUENCE OF WEAK
  VWS. THE SYSTEM WILL THEN MAINTAIN ITS INTENSITY UNTIL FT72 DUE TO
  THE INSUFFICIENT ENVIRONMENT FOR ITS FURTHER DEVELOPMENT DESPITE A
  FAVORABLE ENVIRONMENT UNDER THE INFLUENCE OF WEAK VWS. THE SYSTEM
  WILL THEN WEAKEN UNTIL FT120 DUE TO THE INFLUENCE OF LOW TCHP. THE
  SYSTEM WILL TRANSFORM INTO AN EXTRATROPICAL CYCLONE BY FT120. THE
  INTENSITY FORECAST IS BASED ON A CONSENSUS OF GUIDANCE DATA
  INCLUDING GSM.
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