Tropical Storm FUNG-WONG Advisory Sun Sep 21

MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 16W (FUNG-WONG) WARNING
NR 15//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TROPICAL STORM (TS) 16W (FUNG-WONG), LOCATED APPROXIMATELY 209 NM
SOUTH-SOUTHWEST OF TAIPEI, TAIWAN, HAS TRACKED NORTH-NORTHEASTWARD AT
07 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE
IMAGERY SHOWS THE LOW LEVEL CIRCULATION HAS BECOME PARTIALLY EXPOSED
AS THE SYSTEM MAINTAINED OVERALL WRAP AND CONVECTIVE DEPTH AS IT
APPROACHES TAIWAN. THE INITIAL POSITION IS BASED ON A MICROWAVE EYE
FEATURE ON A 202220Z 37 GHZ SSMIS PASS. THE INITIAL INTENSITY IS
BASED ON CONGRUENT DVORAK ESTIMATES FROM PGTW, KNES, AND RJTD.
UPPER-LEVEL ANALYSIS INDICATES THE SYSTEM IS UNDER THE RIDGE AXIS IN
AN AREA WITH LOW (05 TO 10 KNOT) VERTICAL WIND SHEAR (VWS) AND STRONG
EQUATORWARD OUTFLOW, AS EVIDENT ON WATER VAPOR IMAGERY. TS 16W IS
CURRENTLY TRACKING ALONG THE WESTERN PERIPHERY OF THE SUBTROPICAL
RIDGE (STR) TO THE EAST.
3. FORECAST REASONING.
   A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
   B. TS FUNG-WONG IS FORECAST TO TRACK NORTH-NORTHEASTWARD OVER THE
NEXT 12 HOURS UNDER THE STEERING INFLUENCE OF THE STR AS IT DRAGS
ACROSS WESTERN TAIWAN. AFTERWARDS, THE STR WILL BUILD AND CAUSE THE
CYCLONE TO TRACK MORE NORTHWARD TOWARD THE CHINESE EASTERN SEABOARD.
FAVORABLE UPPER LEVEL CONDITIONS ARE EXPECTED TO PERSIST OVER THE
NEXT 12 HOURS, HOWEVER, INTERACTION WITH THE RUGGED TERRAIN OF
TAIWAN, AND LATER ON WITH THE CHINESE COAST, IN ADDITION TO
INCREASING VWS, WILL ERODE AND EVENTUALLY DISSIPATE THE SYSTEM BY THE
END OF THE FORECAST PERIOD JUST SOUTH OF SHANGHAI. AVAILABLE MODEL
GUIDANCE REMAINS IN FAIRLY TIGHT AGREEMENT LENDING HIGH CONFIDENCE TO
THE JTWC FORECAST.//
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