WTPQ32 RJTD 030600
RSMC TROPICAL CYCLONE PROGNOSTIC REASONING
REASONING NO.42 FOR TS 2509 KROSA (2509)
1.GENERAL COMMENTS
  TS KROSA IS LOCATED AT 40.7N, 154.3E. INFORMATION ON THE CURRENT
  POSITION IS BASED ON ANIMATED MSI AND SURFACE OBSERVATIONS.
  POSITIONAL ACCURACY IS FAIR. CENTRAL PRESSURE IS 980HPA AND
  MAXIMUM SUSTAINED WINDS NEAR THE CENTER ARE 45KNOTS. THE SYSTEM IS
  IN A NEUTRAL ENVIRONMENT FOR DEVELOPMENT UNDER THE INFLUENCE OF
  GOOD UPPER-LEVEL OUTFLOW, LOWER SSTS 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 THE
  SEPARATION OF ACTIVE CONVECTIVE CLOUD CLUSTERS FROM THE CSC.
  ANIMATED MSI SHOWS GOOD CLOUD CHARACTERISTICS OF ANTICYCLONIC
  OUTFLOW. WATER VAPOR IMAGERY SHOWS DRY AIR AROUND THE SYSTEM.
  NOAA-20/ATMS 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 FT24. THE SYSTEM WILL THEN MOVE
  EASTWARD UNDER THE INFLUENCE OF MID-LATITUDE PREVAILING WESTERLIES
  UNTIL FT48. 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 WEAKEN UNTIL FT48 DUE TO THE INFLUENCE OF
  INTERACTION WITH LOW SSTS, LOW TCHP AND STRONG VWS. THE SYSTEM
  WILL TRANSFORM INTO AN EXTRATROPICAL CYCLONE BY FT48. THE
  INTENSITY FORECAST IS BASED ON A CONSENSUS OF GUIDANCE DATA
  INCLUDING GSM.
=