WTPQ32 RJTD 290000
RSMC TROPICAL CYCLONE PROGNOSTIC REASONING
REASONING NO.21 FOR STS 2509 KROSA (2509)
1.GENERAL COMMENTS
  STS KROSA IS LOCATED AT 27.8N, 143.1E. 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 55KNOTS. THE SYSTEM IS
  IN AN UNFAVORABLE ENVIRONMENT FOR DEVELOPMENT UNDER THE INFLUENCE
  OF LOW TCHP AND DRY AIR. THIS HAS CAUSED THE SYSTEM TO WEAKEN 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 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 GOOD CLOUD CHARACTERISTICS OF ANTICYCLONIC OUTFLOW.
  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 SLOWLY NORTHWESTWARD ALONG THE PERIPHERY OF A
  MID-LEVEL SUB-TROPICAL HIGH UNTIL FT12. THE SYSTEM WILL THEN MOVE
  SLOWLY EASTWARD BETWEEN TWO MID-LEVEL SUB-TROPICAL HIGHS UNTIL
  FT24. THE SYSTEM WILL THEN MOVE SLOWLY NORTHEASTWARD UNTIL FT48.
  THE SYSTEM WILL THEN MOVE NORTHWESTWARD UNTIL FT96. THE SYSTEM
  WILL THEN GRADUALLY TURN TO THE NORTHEAST 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 UNTIL FT24 BUT LOW THEREAFTER DUE TO
  SIGNIFICANT DIFFERENCES AMONG NWP MODEL OUTPUTS.
4.INTENSITY FORECAST
  THE SYSTEM WILL GRADUALLY WEAKEN UNTIL FT21 DUE TO THE INFLUENCE
  OF INTERACTION WITH LOW TCHP AND DRY AIR. THE SYSTEM WILL THEN
  MAINTAIN ITS INTENSITY UNTIL FT48 DUE TO THE INFLUENCE OF
  INTERACTION WITH WEAK VWS AND LOW TCHP. THE SYSTEM WILL THEN
  DEVELOP UNTIL FT60 DUE TO THE INFLUENCE OF INTERACTION WITH HIGH
  SSTS AND WEAK VWS. THE SYSTEM WILL THEN MAINTAIN ITS INTENSITY
  UNTIL FT120 DUE TO THE INFLUENCE OF INTERACTION WITH WEAK VWS AND
  LOW TCHP. THE INTENSITY FORECAST IS BASED ON A CONSENSUS OF
  GUIDANCE DATA INCLUDING GSM.
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