WTPQ31 RJTD 241800
RSMC TROPICAL CYCLONE PROGNOSTIC REASONING
REASONING NO. 4 FOR TD LOCATED AT 11.8N 146.8E
1.GENERAL COMMENTS
  A TD IS LOCATED AT 11.8N, 146.8E. INFORMATION ON THE CURRENT
  POSITION IS BASED ON ANIMATED MSI AND SURFACE OBSERVATIONS.
  POSITIONAL ACCURACY IS FAIR. CENTRAL PRESSURE IS 998HPA AND
  MAXIMUM SUSTAINED WINDS NEAR THE CENTER ARE 30KNOTS. THE SYSTEM IS
  IN A FAVORABLE ENVIRONMENT FOR DEVELOPMENT UNDER THE INFLUENCE OF
  HIGH SSTS, HIGH TCHP 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 WESTWARD ALONG THE SOUTHERN PERIPHERY OF A
  MID-LEVEL SUB-TROPICAL HIGH. ANIMATED MSI SHOWS CB CLUSTERS
  GATHERING AROUND THE CSC. WATER VAPOR IMAGERY SHOWS DRY AIR IN THE
  DIRECTION OF THE MOVEMENT. GCOM-W/AMSR2 89 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 DECELERATE AND MOVE WESTWARD UNTIL FT60. THE SYSTEM WILL
  THEN GRADUALLY TURN TO THE NORTHWEST DUE TO INTERACTION WITH A
  NEARBY TROPICAL CYCLONE UNTIL FT120. 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 GRADUALLY DEVELOP UNTIL FT120 DUE TO THE INFLUENCE
  OF INTERACTION WITH HIGH SSTS, HIGH TCHP, WEAK VWS AND DRY AIR.
  THE SYSTEM WILL BE UPGRADED TO TS INTENSITY BY FT12. THE INTENSITY
  FORECAST IS BASED ON A CONSENSUS OF GUIDANCE DATA INCLUDING GSM.
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