WTPQ32 RJTD 261800
RSMC TROPICAL CYCLONE PROGNOSTIC REASONING
REASONING NO.12 FOR TY 2509 KROSA (2509)
1.GENERAL COMMENTS
  TY KROSA IS LOCATED AT 19.5N, 145.2E. INFORMATION ON THE CURRENT
  POSITION IS BASED ON ANIMATED MSI AND SURFACE OBSERVATIONS.
  POSITIONAL ACCURACY IS FAIR. CENTRAL PRESSURE IS 970HPA AND
  MAXIMUM SUSTAINED WINDS NEAR THE CENTER ARE 70KNOTS. THE SYSTEM IS
  IN A FAVORABLE ENVIRONMENT FOR DEVELOPMENT UNDER THE INFLUENCE OF
  HIGH SSTS, HIGH TCHP AND GOOD UPPER-LEVEL OUTFLOW. THIS HAS CAUSED
  THE SYSTEM TO DEVELOP 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 NORTH-NORTHEASTWARD ALONG THE NORTHWESTERN
  PERIPHERY OF A MID-LEVEL SUB-TROPICAL HIGH. ANIMATED MSI SHOWS THE
  ELONGATION OF A BAND WITH A CURVATURE SUGGESTING THE CSC. WATER
  VAPOR IMAGERY SHOWS DRY AIR AROUND THE SYSTEM. NOAA-21/ATMS 85 GHZ
  MICROWAVE IMAGERY SHOWS THE SYSTEM HAS A BAND WITH CURVATURE
  INDICATING THE CSC.
3.TRACK FORECAST
  THE SYSTEM WILL MOVE NORTHWARD ALONG THE PERIPHERY OF A MID-LEVEL
  SUB-TROPICAL HIGH UNTIL FT24. THE SYSTEM WILL THEN GRADUALLY
  DECELERATE AND MOVE NORTHWESTWARD UNTIL FT72. THE SYSTEM WILL THEN
  REMAIN ALMOST STATIONARY UNTIL FT96. THE SYSTEM WILL THEN MOVE
  SLOWLY NORTH-NORTHEASTWARD 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
  INTERACTION WITH HIGH SSTS, HIGH TCHP AND GOOD UPPER-LEVEL
  OUTFLOW. THE SYSTEM WILL THEN GRADUALLY WEAKEN UNTIL FT120 DUE TO
  THE INFLUENCE OF REDUCED TCHP. THE INTENSITY FORECAST IS BASED ON
  A CONSENSUS OF GUIDANCE DATA INCLUDING GSM.
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