WDPN31 PGTW 310300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR SUPER TYPHOON 22W (GONI) 
WARNING NR 013//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   SUPER TYPHOON 22W (GONI), LOCATED APPROXIMATELY 454 NM
EAST OF MANILA, PHILIPPINES, HAS TRACKED WEST-SOUTHWESTWARD 
AT 12 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL
SATELLITE IMAGERY (MSI) DEPICTS A COMPACT, POWERFUL SYSTEM 
WITH A WELL DEFINED 7 NM EYE. WHILE STILL COMPACT IN NATURE
IT HAS INCREASED IN SIZE OVER THE PAST 6 HOURS. THE INITIAL 
POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE WELL 
DEFINED EYE FEATURE IN THE MSI LOOP. THE INITIAL INTENSITY 
OF 160 KTS IS FURTHER PLACED WITH HIGH CONFIDENCE AND IS 
HEDGED SLIGHTLY ABOVE MULTI-AGENCY DVORAK CURRENT INTENSITY 
ESTIMATES OF T7.5 (155 KTS, PGTW AND RJTD) BASED ON RECENT 
ADVANCED DVORAK TECHNIQUE CURRENT INTENSITY ESTIMATES OF T7.6 
(158 KTS). ANALYSIS OF THE EYE WALL STRUCTURES IN SEVERAL 
MICROWAVE IMAGES SUGGESTS THAT AN EYE WALL REPLACEMENT CYCLE 
(ERC) IS IMMINENT. DESPITE THIS, THE OVERALL CONVECTIVE 
STRUCTURE, CLOUD TOP AND EYE TEMPERATURES ARE IN AGREEMENT 
THAT A WEAKENING PHASE, TYPICAL OF ERC, HAS NOT YET COMMENCED. 
STY GONI HAS CONTINUED TO TRACK ALONG THE SOUTHERN PERIPHERY 
OF THE SUBTROPICAL RIDGE (STR) POSITIONED OVER SOUTHERN CHINA 
AND THROUGH AN OVERALL FAVORABLE ENVIRONMENT WITH VERY WARM 
(30 DEG CELSIUS) WATERS, LOW (10-15 KNOTS) VWS AND ROBUST 
RADIAL OUTFLOW. POLEWARD OUTFLOW REMAINS ESPECIALLY STRONG.  
3. FORECAST REASONING.
   A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS
PROGNOSTIC REASONING MESSAGE.
   B. STY GONI WILL CONTINUE TO TRACK GENERALLY SOUTHWESTWARD
TO SOUTH-SOUTHWESTWARD OVER THE NEXT 24 HOURS. THE ENVIRONMENT
WILL REMAIN OVERALL FAVORABLE FOR DEVELOPMENT, HOWEVER A
GRADUAL WEAKENING IS FORECAST DURING THIS TIME DUE TO THE ERC
AND, DECREASING POLEWARD OUTFLOW ASSOCIATED WITH THE ONGOING
REPOSITIONING OF THE STEERING RIDGE, AND A SMALL INCREASE IN 
VWS (15-20 KTS). STY GONI WILL THEN MAKE LANDFALL ALONG THE
COAST OF LUZON, EAST OF MANILA, BETWEEN TAU 24 AND TAU 36 AS A 
SIGNIFICANT TROPICAL CYCLONE. AS THE SYSTEM TRANSITS ACROSS 
LUZON AND INTO THE SOUTH CHINA SEA, IT WILL FURTHER WEAKEN DUE 
TO TERRAIN INTERACTION TO AN INTENSITY OF 75 KTS BY TAU 48. AS 
THE SYSTEM TRACKS OVER THE SOUTH CHINA SEA BETWEEN TAU 48 AND 
TAU 72, IT WILL STEADILY WEAKEN TO AN INTENSITY OF 60 KTS DUE 
TO CONTINUED MODERATE TO HIGH (20-25 KTS) VWS. NUMERICAL MODEL 
GUIDANCE IS IN GOOD AGREEMENT DURING THIS INITIAL PORTION OF 
THE JTWC FORECAST TRACK, WITH A TOTAL SPREAD IN ACROSS TRACK 
MODEL SOLUTIONS OF 150 NM AT TAU 72. SPECIFICALLY THE NAVGEM 
TRACK LIES NORTHWARD OF THE OTHER JTWC MULTI-MODEL CONSENSUS 
MEMBERS. AS SUCH, THIS INITIAL PORTION OF THE JTWC FORECAST IS 
PLACED SLIGHTLY SOUTH OF THE JTWC MULTI-MODEL CONSENSUS WITH 
OVERALL HIGH CONFIDENCE.
   C. IN THE EXTENDED FORECAST, THE SYSTEM WILL TRACK WESTWARD 
ALONG THE SOUTHERN PERIPHERY OF THE DEEP-LAYER STR POSITIONED 
TO THE NORTH THROUGH THE END OF THE FORECAST, AND MAKE A SECOND 
LANDFALL ALONG THE CENTRAL VIETNAM COAST BETWEEN TAU 96 AND TAU 
120. THE SYSTEM WILL CONTINUE TO WEAKEN UNDER THE INFLUENCE OF 
MODERATE VWS AND CONTINUED ENTRAINMENT OF DRY MID-LEVEL AIR. 
NUMERICAL MODEL TRACK GUIDANCE HAS CONVERGED SINCE THE LAST 
FORECAST WITH ONLY NAVGEM PREDICTING A NORTHWESTWARD TRACK
TOWARDS HAINAN. THE REMAINING MEMBERS OF THE JTWC MULTI-MODEL
CONSENSUS AGREE WITH A WESTWARD TRACK DURING THIS TIME. AS SUCH
THE JTWC FORECAST TRACK FOR THE REMAINDER OF THE FORECAST IS
PLACED SOUTH OF THE MULTI-MODEL CONSENSUS WITH OVERALL FAIR
CONFIDENCE TO OFFSET THE NORTHWESTWARD BIAS CONTRIBUTED BY THE
NAVGEM TRACK.//
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