WTPQ33 RJTD 131200
RSMC TROPICAL CYCLONE PROGNOSTIC REASONING
REASONING NO.15 FOR TY 2425 USAGI (2425)
1.GENERAL COMMENTS
  TY USAGI IS LOCATED AT 16.1N, 125.4E. INFORMATION ON THE CURRENT
  POSITION IS BASED ON THE EYE IN ANIMATED MSI AND SURFACE
  OBSERVATIONS. POSITIONAL ACCURACY IS GOOD. CENTRAL PRESSURE IS
  955HPA AND MAXIMUM SUSTAINED WINDS NEAR THE CENTER ARE 80KNOTS.
  THE SYSTEM IS IN A FAVORABLE ENVIRONMENT FOR DEVELOPMENT UNDER THE
  INFLUENCE OF HIGH SSTS, HIGH TCHP, WEAK VWS AND GOOD UPPER-LEVEL
  OUTFLOW. THIS HAS CAUSED THE SYSTEM TO DEVELOP OVER THE LAST SIX
  HOURS. IT HAS ALSO DEVELOPED RAPIDLY OVER THE LAST 12 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
  APPEARANCE OF AN EYE. ANIMATED MSI SHOWS GOOD CLOUD
  CHARACTERISTICS OF ANTICYCLONIC OUTFLOW. WATER VAPOR IMAGERY SHOWS
  DRY AIR AROUND THE SYSTEM. GPM/GMI 89 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 DEVELOP UNTIL FT12 DUE TO THE INFLUENCE OF
  INTERACTION WITH HIGH SSTS, HIGH TCHP, WEAK VWS AND GOOD
  UPPER-LEVEL OUTFLOW. THE SYSTEM WILL THEN MAINTAIN ITS INTENSITY
  UNTIL FT24 DUE TO THE INFLUENCE OF INTERACTION WITH HIGH SSTS,
  WEAK VWS, REDUCED TCHP AND LAND. THE SYSTEM WILL THEN WEAKEN UNTIL
  FT120 DUE TO THE INFLUENCE OF INTERACTION WITH INCREASED VWS AND
  LAND. THE INTENSITY FORECAST IS BASED ON A CONSENSUS OF GUIDANCE
  DATA INCLUDING GSM.
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