WDPN31 PGTW 211500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 16W (GONI) WARNING NR 31//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TYPHOON (TY) 16W (GONI), LOCATED APPROXIMATELY 345 NM SOUTH OF 
TAIPEI, TAIWAN, HAS TRACKED NORTHWARD AT 01 KNOT OVER THE PAST SIX 
HOURS. ANIMATED ENHANCED IR SATELLITE IMAGERY DEPICTS A CLOUD-FILLED 
12 NM EYE WITH GOOD CONFIDENCE IN THE CURRENT POSITION. A 211028Z 
SSMIS IMAGE SHOWS A PARTIAL EYEWALL WITH TIGHTLY-CURVED BANDING 
LOCATED PRIMARILY OVER THE SOUTHERN SEMI-CIRCLE. UPPER-LEVEL 
ANALYSIS INDICATES NEAR-RADIAL OUTFLOW WITH WEAK CONVERGENT FLOW AND 
MODERATE NORTHERLY VERTICAL WIND SHEAR OVER THE NORTHERN PERIPHERY 
OF THE SYSTEM. THE CURRENT INTENSITY IS ASSESSED AT 95 KNOTS BASED 
ON DVORAK CURRENT INTENSITY ESTIMATES RANGING FROM ALL AGENCIES. TY 
16W IS NEARLY STATIONARY, POSSIBLY TROCHOIDAL MOVEMENT, ALONG THE 
SOUTHERN PERIPHERY OF A WEAK NARROW STR TO THE NORTH.
3. FORECAST REASONING.
   A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS 
PROGNOSTIC REASONING MESSAGE.
   B. TY 16W IS FORECAST TO REMAIN NEARLY STATIONARY OVER THE NEXT 
12 HOURS, WITH THE POTENTIAL TO SPEED UP SLIGHTLY, AS THE STEERING 
ENVIRONMENT REMAINS WEAK. THE RECENT 500 MB ANALYSIS, AS WELL AS 
WATER-VAPOR IMAGERY, SHOWS THE STR TO THE NORTH CONTINUING TO 
WEAKENING. AFTER TAU 12, THE STR IS FORECAST TO RE-BUILD EAST OF THE 
SYSTEM PROVIDING A POLEWARD ORIENTED TRACK, WHICH SHOULD ALLOW THE 
SYSTEM TO SLOWLY TRACK NORTHWARD. TY 16W SHOULD WEAKEN GRADUALLY 
THROUGH THE FORECAST PERIOD DUE TO LAND INTERACTION AND INCREASED 
UPPER-LEVEL CONVERGENCE ASSOCIATED WITH THE UPPER-LEVEL SUBTROPICAL 
WESTERLIES ENCROACHING ON THE WESTERN PERIPHERY OF THE SYSTEM.
   C. IN THE EXTENDED PERIOD, TY 16W WILL TURN NORTHEASTWARD AS IT 
TRACKS ALONG THE NORTHWESTERN PERIPHERY OF THE STR. TY GONI WILL 
WEAKEN SIGNIFICANTLY AS IT TRACK THOUGH SOUTHERN JAPAN AND INTO THE 
COOL WATERS OF THE SEA OF JAPAN. ADDITIONALLY, THE SYSTEM WILL BEGIN 
SLIGHT INTERACTION WITH THE BAROCLINC ZONE BY TAU 96 AND COMPLETING 
ETT BY THE END OF THE FORECAST PERIOD, BEING COMPLETELY ENVELOPED BY 
THE WESTERLIES. DYNAMIC GUIDANCE IS IN GOOD AGREEMENT, HOWEVER, DUE 
TO THE COMPLEX STEERING ENVIRONMENT IN THE EARLY PORTION OF THE 
FORECAST, THERE REMAINS  LOW CONFIDENCE IN THE JTWC FORECAST TRACK.//
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