WDPN31 PGTW 291500
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 22W (GONI) WARNING NR 
007//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TYPHOON 22W (GONI), LOCATED APPROXIMATELY 796 NM EAST OF MANILA, 
PHILIPPINES, HAS TRACKED WESTWARD AT 12 KNOTS OVER THE PAST SIX 
HOURS. ANIMATED MULTISPECTRAL ENHANCED INFRARED SATELLITE IMAGERY 
SHOWS A VERY COMPACT SYSTEM THAT CONTINUES TO RAPIDLY INTENSIFY, 
WITH A NASCENT EYE FEATURE STARTING TO FORM JUST AFTER THE 1200Z 
HOUR. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON 
TIMELY RECEIPT OF A 291200Z ASCAT-B BULLSEYE PASS, WHICH CLARIFIED 
THE LLCC WHICH AT THAT TIME WAS STILL OBSCURED BY A CDO. THE INITIAL 
INTENSITY IS SET WITH MODERATE CONFIDENCE AT 80 KNOTS, HEDGED HIGHER 
THAN THE MULTI-AGENCY DVORAK CURRENT INTENSITY ESTIMATES OF T4.0 (65 
KNOTS) FROM PGTW, RJTD AND KNES, WHICH ARE LAGGING BEHIND THE 
ADVANCED DVORAK TECHNIQUE ESTIMATE OF T4.7 (82 KNOTS) DUE TO THE 
VERY COMPACT NATURE OF THE SYSTEM. TY 22W IS TRACKING WESTWARD UNDER 
THE STEERING INFLUENCE OF A LARGE, DEEP-LAYER SUBTROPICAL RIDGE 
(STR) WITH A NEW CENTER DEVELOPING JUST NORTHEAST OF TY 22W, PUSHING 
IT BACK ONTO A WESTERLY COURSE A BIT FASTER THAN ANTICIPATED. TY 
GONI CONTINUES MOVING THROUGH AN ENVIRONMENT THAT IS HIGHLY 
FAVORABLE FOR ADDITIONAL RAPID INTENSIFICATION, WITH VERY WARM (30-
31 DEG CELSIUS) WATERS WITH HIGH OHC VALUES (GREATER THAN 150), LOW 
(5-10 KNOTS) VWS AND ROBUST RADIAL OUTFLOW WITH THE POLEWARD OUTFLOW 
BEING ENHANCED AS IT TAPS INTO A AN UPPER-LEVEL MID-LATITUDE TROUGH 
PASSING BY TO THE NORTH.
3. FORECAST REASONING.
   A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS 
PROGNOSTIC REASONING MESSAGE.. 
   B. TY 22W WILL CONTINUE TRACKING GENERALLY WESTWARD THROUGH TAU 
12 UNDER THE STEERING INFLUENCE OF THE STR CENTER LOCATED TO THE 
NORTHEAST. BY TAU 24 THE SYSTEM WILL TURN ONTO A WEST-SOUTHWEST THEN 
SOUTHWESTERLY TRACK AS THE PRIMARY STEERING MECHANISM SHIFTS TO THE 
STR CENTER LOCATED OVER FAR SOUTHERN CHINA. BY TAU 72 THE SYSTEM 
RESUMES A WEST TO SLIGHTLY WEST-NORTHWEST TRACK AS THE STEERING 
PATTERN SHIFTS ONCE MORE TO THE STR CENTER TO THE NORTHEAST. TY 22W 
IS FORECAST TO CONTINUE ITS RAPID INTENSIFICATION THROUGH TAU 36 
UNDER VERY FAVORABLE CONDITIONS OF VERY WARM (31 DEG CELSIUS) SSTS 
AND VERY HIGH (GREATER THAN 150) OHC, AND LOW (5 TO 10 KNOTS) VWS, 
PEAKING AT 130 KNOTS AT TAU 48. INCREASING VWS IN CONJUNCTION WITH 
WEAKER AND LESS DIVERGENT OUTFLOW ALOFT WILL COMBINE TO BEGIN A 
STEADY WEAKENING TREND WITH THE SYSTEM WEAKENING TO 115 KNOTS BY TAU 
72. DYNAMIC MODEL GUIDANCE IS IN GOOD AGREEMENT WITH THE NOTABLE 
EXCEPTION OF NAVGEM, WHICH CONTINUES ITS TREND OF BEING WELL NORTH 
OF THE REMAINDER OF THE GUIDANCE PACKAGE. WHEN DISCOUNTING NAVGEM, 
THE SPREAD AT TAU 72 IS JUST 80 NM, INCREASING TO 130 NM IF NAVGEM 
IS INCLUDED. THE JTWC FORECAST TRACK LIES ALONG THE NORTHERN SIDE OF 
THE GUIDANCE ENVELOPE THROUGH TAU 72 WITH HIGH CONFIDENCE. INTENSITY 
GUIDANCE CONTINUES TO STRONGLY INDICATE EXTREMELY RAPID 
INTENSIFICATION AND THE JTWC FORECAST LIES ABOVE THE MAJORITY OF THE 
INTENSITY CONSENSUS, CLOSE THE HWRF SOLUTION WITH HIGH CONFIDENCE.  
   C. BEYOND TAU 72, THE SYSTEM WILL TURN TOWARDS THE WEST-NORTHWEST 
IN RESPONSE TO A SLIGHT WEAKENING IN THE STR, WITH LANDFALL IN 
CENTRAL LUZON EXPECTED AROUND TAU 84 AS A SIGNIFICANT TROPICAL 
CYCLONE. AFTER LANDFALL AND TRANSIT ACROSS THE MOUNTAINOUS TERRAIN 
OF CENTRAL LUZON, THE SYSTEM WILL REEMERGE INTO THE SOUTH CHINA SEA 
PRIOR TO TAU 96, ALBEIT AS A SIGNIFICANTLY WEAKENED TYPHOON DUE TO 
COMBINED EFFECTS OF TERRAIN INTERACTION, INCREASED VWS AND 
ENTRAINMENT OF COOLER AND DRIER AIR FROM THE NORTHEAST. THROUGH TAU 
120, THE SYSTEM WILL CONTINUE TO WEAKEN UNDER THE INFLUENCE OF 
MODERATE VWS AND CONTINUED ENTRAINMENT OF DRY MID-LEVEL AIR. DYNAMIC 
MODEL GUIDANCE REMAINS IN GOOD OVERALL AGREEMENT THOUGH THE END OF 
THE FORECAST WITH A CROSS-TRACK SPREAD OF 150 NM AT TAU 120. 
HOWEVER, THE MODELS CONTINUE TO SHOW A FAIRLY LARGE AMOUNT OF ALONG-
TRACK SPREAD AFTER TAU 96, AND THE JTWC FORECAST TRACK LIES ALONG 
THE NORTHERN EDGE OF THE MODEL GUIDANCE AND SLIGHTLY SLOWER THAN THE 
MULTI-MODEL CONSENSUS WITH OVERALL LOW CONFIDENCE DUE TO THE 
INCREASING ALONG-TRACK SPREAD.//
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