WTPQ31 RJTD 091200
RSMC TROPICAL CYCLONE PROGNOSTIC REASONING
REASONING NO.22 FOR TY 2522 HALONG (2522)
1.GENERAL COMMENTS
  TY HALONG IS LOCATED AT 34.1N, 146.9E. INFORMATION ON THE CURRENT
  POSITION IS BASED ON ANIMATED MSI AND SURFACE OBSERVATIONS.
  POSITIONAL ACCURACY IS FAIR. CENTRAL PRESSURE IS 960HPA AND
  MAXIMUM SUSTAINED WINDS NEAR THE CENTER ARE 80KNOTS. THE SYSTEM IS
  IN AN UNFAVORABLE ENVIRONMENT FOR DEVELOPMENT UNDER THE INFLUENCE
  OF LOWER SSTS, LOW TCHP AND STRONG VWS. 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 EASTWARD ALONG THE NORTHERN PERIPHERY OF A
  MID-LEVEL SUB-TROPICAL HIGH. ANIMATED MSI SHOWS THE EYE HAS
  DISAPPEARED. 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
  A BAND WITH CURVATURE INDICATING THE CSC.
3.TRACK FORECAST
  THE SYSTEM WILL MOVE EASTWARD ALONG THE PERIPHERY OF A MID-LEVEL
  SUB-TROPICAL HIGH UNTIL FT12. THE SYSTEM WILL THEN GRADUALLY
  ACCELERATE AND MOVE EASTWARD UNDER THE INFLUENCE OF MID-LATITUDE
  PREVAILING WESTERLIES UNTIL FT24. 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 FT24 DUE TO THE INFLUENCE OF
  INTERACTION WITH LOWER SSTS, LOW TCHP AND STRONG VWS. THE SYSTEM
  WILL TRANSFORM INTO AN EXTRATROPICAL CYCLONE BY FT24. THE
  INTENSITY FORECAST IS BASED ON A CONSENSUS OF GUIDANCE DATA
  INCLUDING GSM.
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