13W JTWC:熱帶風暴 - 颱風討論

http://www.usno.navy.mil/NOOC/nmfc-ph/RSS/jtwc/warnings/wp1312.gif

WDPN31 PGTW 051500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 13W (THIRTEEN)
WARNING NR 04//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
TROPICAL STORM 13W (THIRTEEN), LOCATED APPROXIMATELY 390 NM
NORTHWEST OF WAKE ISLAND, HAS TRACKED NORTH-NORTHEASTWARD AT 11
KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE
IMAGERY SHOWS THE SYSTEM HAS MAINTAINED ITS CENTRAL DEEP CONVECTION.
THE INITIAL POSITION WAS BASED ON THE ABOVE ANIMATION AND
EXTRAPOLATED FROM A 050941Z AMSU-B MICROWAVE IMAGE WITH POOR
CONFIDENCE. THE INITIAL INTENSITY WAS BASED ON A DVORAK ESTIMATE FROM
PGTW. UPPER LEVEL ANALYSIS INDICATES THE SYSTEM IS TO THE NORTH
AND WEST OF RIDGE AXES IN AN AREA OF LOW TO MODERATE (10-15 KNOT)
VERTICAL WIND SHEAR (VWS). THE CYCLONE IS TRACKING UNDER THE STEERING
INFLUENCE OF A BUILDING SUBTROPICAL RIDGE TO THE NORTHEAST.
3. FORECAST REASONING.
A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY FROM THE PREVIOUS
PROGNOSTIC REASONING BULLETIN.
B. TS 13W IS EXPECTED TO CONTINUE TRACKING NORTHWARD UP TO TAU
48. DURING THIS TIME FRAME, THE STORM WILL SEE A SLIGHT
INTENSIFICATION AS UPPER LEVEL CONDITIONS AND SEA SURFACE
TEMPERATURES REMAIN FAVORABLE. AFTER TAU 48, THE STEERING RIDGE IS
EXPECTED TO EXTEND WESTWARD AND CAUSE THE CYCLONE TO TRACK ON A MORE
WESTWARD TRAJECTORY. THIS WILL PLACE THE STORM MOTION IN SHARP
CONTRAST WITH UPPER LEVEL FLOW, RESULTING IN HIGHER VWS WHICH WILL
CAUSE THE GRADUAL WEAKENING OF THE SYSTEM.
C. BEYOND TAU 72, DECREASING SST'S AND PERSISTENTLY HIGH VWS WILL
ERODE THE SYSTEM DOWN TO A 25-KNOT SYSTEM BY END OF FORECAST PERIOD.
THERE IS HIGH CONFIDENCE IN THE TRACK FORECAST UP TO TAU 48, AFTER
TAU 48, THE NUMERICAL MODELS SIGNIFICANTLY DIVERGE. GFDN, NOGAPS, AND
GFS BRING THE VORTEX POLEWARD INTO THE BUILDING RIDGE, AN UNLIKELY
SCENARIO. THE JTWC WESTWARD TRACK FORECAST AFTER TAU 48 IN RESPONSE
TO A BUILDING RIDGE, IS CLOSER TO THE ECMWF SOLUTION. DUE TO THE
VARIANCE IN THE MODEL GUIDANCE, THERE IS A LOW CONFIDENCE IN THE
TRACK FORECAST AFTER TAU 48. //
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這是直接跳過TD
直升TS嗎
終於贏了JMA一次嗎 XD
路徑跟強度都不值得提的樣子
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