WTPQ32 RJTD 310000
RSMC TROPICAL CYCLONE PROGNOSTIC REASONING
REASONING NO.29 FOR STS 2509 KROSA (2509)
1.GENERAL COMMENTS
  STS KROSA IS LOCATED AT 30.1N, 142.9E. 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 MOVING SLOWLY NORTH-NORTHWESTWARD BETWEEN TWO
  MID-LEVEL SUB-TROPICAL HIGHS. 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 IN THE DIRECTION OF THE MOVEMENT. DMSP-F17/SSMIS 89
  GHZ MICROWAVE IMAGERY SHOWS THE SYSTEM HAS A BAND WITH CURVATURE
  INDICATING THE CSC.
3.TRACK FORECAST
  THE SYSTEM WILL MOVE NORTHWARD 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 FAIR UNTIL FT24 BUT
  LOW THEREAFTER DUE TO SIGNIFICANT DIFFERENCES AMONG NWP MODEL
  OUTPUTS.
4.INTENSITY FORECAST
  THE SYSTEM WILL GRADUALLY DEVELOP UNTIL FT48 DUE TO THE INFLUENCE
  OF INTERACTION WITH HIGH SSTS AND WEAK VWS. THE SYSTEM WILL THEN
  WEAKEN UNTIL FT120 DUE TO THE INFLUENCE OF INTERACTION WITH LOWER
  SSTS AND 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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