WTPQ32 RJTD 021200
RSMC TROPICAL CYCLONE PROGNOSTIC REASONING
REASONING NO.39 FOR STS 2509 KROSA (2509)
1.GENERAL COMMENTS
  STS KROSA IS LOCATED AT 38.3N, 145.8E. INFORMATION ON THE CURRENT
  POSITION IS BASED ON ANIMATED MSI AND SURFACE OBSERVATIONS.
  POSITIONAL ACCURACY IS GOOD. CENTRAL PRESSURE IS 975HPA AND
  MAXIMUM SUSTAINED WINDS NEAR THE CENTER ARE 50KNOTS. THE SYSTEM IS
  IN A NEUTRAL ENVIRONMENT FOR DEVELOPMENT UNDER THE INFLUENCE OF
  GOOD UPPER-LEVEL OUTFLOW 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 EAST-NORTHEASTWARD ALONG THE NORTHWESTERN
  PERIPHERY OF A MID-LEVEL SUB-TROPICAL HIGH. ANIMATED MSI SHOWS CB
  CLUSTERS GATHERING AROUND THE CSC. ANIMATED MSI SHOWS GOOD CLOUD
  CHARACTERISTICS OF ANTICYCLONIC OUTFLOW. WATER VAPOR IMAGERY SHOWS
  DRY AIR AROUND THE SYSTEM. METOP-B/MHS 85 GHZ MICROWAVE IMAGERY
  SHOWS THE SYSTEM HAS ACTIVE CONVECTIVE CLOUD CLUSTERS AROUND THE
  CSC.
3.TRACK FORECAST
  THE SYSTEM WILL MOVE EAST-NORTHEASTWARD ALONG THE PERIPHERY OF A
  MID-LEVEL SUB-TROPICAL HIGH UNTIL FT72. THE TRACK FORECAST IS
  BASED ON GSM PREDICTIONS, AND REFERENCE TO OTHER NWP MODELS. TRACK
  FORECAST CONFIDENCE IS FAIR 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 GOOD UPPER-LEVEL OUTFLOW AND LOW
  TCHP. THE SYSTEM WILL THEN WEAKEN UNTIL FT72 DUE TO THE INFLUENCE
  OF INTERACTION WITH LOW SSTS, LOW TCHP AND INCREASED VWS. THE
  SYSTEM WILL TRANSFORM INTO AN EXTRATROPICAL CYCLONE BY FT72. THE
  INTENSITY FORECAST IS BASED ON A CONSENSUS OF GUIDANCE DATA
  INCLUDING GSM.
=