WTPQ33 RJTD 131800
RSMC TROPICAL CYCLONE PROGNOSTIC REASONING
REASONING NO.16 FOR TY 2425 USAGI (2425)
1.GENERAL COMMENTS
  TY USAGI IS LOCATED AT 16.6N, 123.9E. INFORMATION ON THE CURRENT
  POSITION IS BASED ON THE EYE IN ANIMATED MSI AND SURFACE
  OBSERVATIONS. POSITIONAL ACCURACY IS GOOD. CENTRAL PRESSURE IS
  950HPA AND MAXIMUM SUSTAINED WINDS NEAR THE CENTER ARE 90KNOTS.
  THE SYSTEM IS IN A FAVORABLE ENVIRONMENT FOR DEVELOPMENT UNDER THE
  INFLUENCE OF HIGH SSTS, HIGH TCHP AND WEAK VWS. THIS HAS CAUSED
  THE SYSTEM TO DEVELOP OVER THE LAST SIX HOURS. IT HAS ALSO
  DEVELOPED RAPIDLY OVER THE LAST 24 HOURS. INFORMATION ON THE
  CURRENT INTENSITY IS BASED ON DVORAK INTENSITY ANALYSES AND
  SURFACE OBSERVATIONS.
2.SYNOPTIC SITUATION
  THE SYSTEM IS MOVING WEST-NORTHWESTWARD ALONG THE SOUTHWESTERN
  PERIPHERY OF A MID-LEVEL SUB-TROPICAL HIGH. ANIMATED MSI SHOWS THE
  EYE HAS BECOME DISTINCT. ANIMATED MSI SHOWS GOOD CLOUD
  CHARACTERISTICS OF ANTICYCLONIC OUTFLOW. WATER VAPOR IMAGERY SHOWS
  DRY AIR AROUND THE SYSTEM. NOAA-19/MHS 85 GHZ MICROWAVE IMAGERY
  SHOWS THE SYSTEM HAS A BAND WITH CURVATURE INDICATING THE CSC.
3.TRACK FORECAST
  THE SYSTEM WILL GRADUALLY TURN TO THE NORTH ALONG THE PERIPHERY OF
  A MID-LEVEL SUB-TROPICAL HIGH UNTIL FT48. THE SYSTEM WILL THEN
  MOVE SLOWLY NORTHEASTWARD DUE TO WEAK STEERING FLOW UNTIL FT120.
  THE TRACK FORECAST IS BASED ON GSM PREDICTIONS, AND REFERENCE TO
  OTHER NWP MODELS. TRACK FORECAST CONFIDENCE IS FAIR UNTIL FT48 BUT
  LOW THEREAFTER DUE TO SIGNIFICANT DIFFERENCES AMONG NWP MODEL
  OUTPUTS.
4.INTENSITY FORECAST
  THE SYSTEM WILL MAINTAIN ITS INTENSITY UNTIL FT12 DUE TO THE
  INFLUENCE OF INTERACTION WITH HIGH SSTS, HIGH TCHP, WEAK VWS AND
  LAND. THE SYSTEM WILL THEN WEAKEN UNTIL FT120 DUE TO THE INFLUENCE
  OF INTERACTION WITH INCREASED VWS AND LAND. THE SYSTEM WILL WEAKEN
  TO TD INTENSITY BY FT120. THE INTENSITY FORECAST IS BASED ON A
  CONSENSUS OF GUIDANCE DATA INCLUDING GSM.
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