Tropical Storm GONI Advisory Thu Aug 20

MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TYPHOON 16W (GONI) WARNING NR 23//
RMKS//
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TYPHOON (TY) 16W (GONI), LOCATED APPROXIMATELY 457 NM SOUTH OF
KADENA AB, OKINAWA, JAPAN, HAS TRACKED WESTWARD AT 10 KNOTS OVER THE
PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY SHOWS THE
SYSTEM HAS BECOME MORE SYMMETRICAL AS CURVED BANDING WRAPPED TIGHTER
INTO A 17-NM DIAMETER EYE. ADDITIONALLY, CONVECTIVE TOPS ALONG THE EYE
WALL HAVE DEEPENED. THE INITIAL POSITION IS BASED ON THE EYE FEATURE
WITH HIGH CONFIDENCE. THE INITIAL INTENSITY OF 110 KNOTS IS BASED ON
AN OVERALL ASSESSMENT OF DVORAK INTENSITY ESTIMATES FROM ALL REPORTING
AGENCIES AND REFLECTS THE IMPROVED STATE OF THE CYCLONE. UPPER-LEVEL
ANALYSIS INDICATES LOW TO MODERATE (10 TO 20 KNOT) VWS THAT IS OFFSET
BY STRONG EQUATORWARD OUTFLOW. TY 16W IS TRACKING ALONG THE SOUTHERN
PERIPHERY OF THE DEEP STR TO THE NORTH.
3. FORECAST REASONING.
   A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
   B. TY 16W WILL CONTINUE TO TRACK GENERALLY WESTWARD THROUGH TAU
36 UNDER THE STEERING INFLUENCE OF THE STR. AFTERWARD, AN UPPER-
LEVEL TROUGH PASSING TO THE NORTH WILL CAUSE A BREAK IN THE STR,
SHIFTING TY 16W POLEWARD. FAVORABLE CONDITIONS ALONG WITH IMPROVING
POLEWARD OUTFLOW WILL PROMOTE STEADY INTENSIFICATION, LEADING TO A
PEAK 125 KNOTS BY TAU 36. AFTERWARD, INCREASING VWS AND LOWER OHC
VALUES WILL BEGIN TO WEAKEN THE SYSTEM.
   C. IN THE EXTENDED TAUS, TY GONI WILL CONTINUE TO TRACK POLEWARD
DUE TO A BREAK IN THE STR. WEAKENING TREND IS EXPECTED AS DEGRADED
CONDITIONS PERSIST. AVAILABLE MODEL GUIDANCE REMAINS IN GOOD
AGREEMENT THROUGH TAU 48, BUT CONTINUES TO SHOW A SPREAD IN THE
LATER TAUS. DUE TO THE UNCERTAINTY IN THE TIMING OF THE POLEWARD
TURN AND THE DEGREE OF SPREAD IN THE LATER TAUS, THE JTWC TRACK
FORECAST CONFIDENCE LEVEL REMAINS LOW.//
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