WTPQ31 RJTD 050600
RSMC TROPICAL CYCLONE PROGNOSTIC REASONING
REASONING NO. 5 FOR TS 2522 HALONG (2522)
1.GENERAL COMMENTS
  TS HALONG IS LOCATED AT 24.8N, 142.3E. INFORMATION ON THE CURRENT
  POSITION IS BASED ON ANIMATED MSI AND SURFACE OBSERVATIONS.
  POSITIONAL ACCURACY IS FAIR. CENTRAL PRESSURE IS 1000HPA AND
  MAXIMUM SUSTAINED WINDS NEAR THE CENTER ARE 35KNOTS. THE SYSTEM IS
  IN A FAVORABLE ENVIRONMENT FOR DEVELOPMENT UNDER THE INFLUENCE OF
  HIGH SSTS, HIGH TCHP, WEAK VWS AND GOOD UPPER-LEVEL OUTFLOW.
  HOWEVER, THE LIMITED FIRMNESS OF ITS STRUCTURE HAS CAUSED IT 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 WESTWARD ALONG THE SOUTHERN PERIPHERY
  OF A MID-LEVEL SUB-TROPICAL HIGH. ANIMATED MSI SHOWS CB CLUSTERS
  GATHERING AROUND THE CSC AND FORMING A CURVED BAND. ANIMATED MSI
  SHOWS THE CLOUD CHARACTERISTICS OF ANTICYCLONIC OUTFLOW ARE NOW
  DISTINCT. WATER VAPOR IMAGERY SHOWS DRY AIR IN THE DIRECTION OF
  THE MOVEMENT. NOAA-21/ATMS 85 GHZ MICROWAVE IMAGERY SHOWS THE
  SYSTEM HAS ACTIVE CONVECTIVE CLOUD CLUSTERS AROUND THE CSC.
3.TRACK FORECAST
  THE SYSTEM WILL MOVE WEST-NORTHWESTWARD ALONG THE PERIPHERY OF A
  MID-LEVEL SUB-TROPICAL HIGH UNTIL FT48. THE SYSTEM WILL THEN
  GRADUALLY TURN TO THE NORTH BETWEEN TWO MID-LEVEL SUB-TROPICAL
  HIGHS UNTIL FT96. THE SYSTEM WILL THEN MOVE EAST-NORTHEASTWARD
  UNDER THE INFLUENCE OF MID-LATITUDE PREVAILING WESTERLIES 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 FT96 DUE TO THE INFLUENCE OF
  INTERACTION WITH HIGH SSTS, HIGH TCHP AND WEAK VWS. THE SYSTEM
  WILL THEN MAINTAIN ITS INTENSITY UNTIL FT120 DUE TO THE INFLUENCE
  OF INTERACTION WITH GOOD UPPER-LEVEL OUTFLOW AND STRONG VWS. THE
  INTENSITY FORECAST IS BASED ON A CONSENSUS OF GUIDANCE DATA
  INCLUDING GSM.
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