WDPN31 PGTW 060300
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 09W (CHAN-HOM) WARNING 
NR 23//
RMKS/
1. FOR METEOROLOGISTS.
2. 6 HOUR SUMMARY AND ANALYSIS.
   TROPICAL STORM (TS) 09W (CHAN-HOM), LOCATED APPROXIMATELY 1019 NM
SOUTHEAST OF KADENA AB, HAS TRACKED NORTH-NORTHWESTWARD AT 08 KNOTS 
OVER THE PAST SIX HOURS. RECENT MSI CONTINUES TO DEPICT DEEPENED 
CENTRAL CONVECTION WITH TIGHTLY-CURVED BANDING WRAPPING INTO A 
CONSOLIDATING LLCC. THE CURRENT POSITION IS BASED ON THE MSI AS WELL 
AS A 060030Z METOP-B WITH HIGH CONFIDENCE. THE CURRENT INTENSITY HAS 
INCREASED TO 55 KNOTS BASED ON THE IMPROVING STRUCTURE AND 
CORRESPONDING DVORAK INTENSITY ESTIMATES OF T3.5 FROM PGTW AND RJTD. 
UPPER-LEVEL ANALYSIS INDICATES TS 09W IS NOW LOCATED IN A FAVORABLE 
ENVIRONMENT WITH LOW VWS AND RADIAL OUTFLOW AS EVIDENT ON THE WATER 
VAPOR IMAGERY. TS 09W IS TRACKING ALONG THE SOUTHERN PERIPHERY OF 
THE DEEP-LAYERED STR.
3. FORECAST REASONING.
   A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS 
PROGNOSTIC REASONING MESSAGE.
   B. TS 09W IS FORECAST TO RESUME A WEST-NORTHWESTWARD TO 
NORTHWESTWARD TRAJECTORY UNDER THE STEERING INFLUENCE OF THE STR 
ENTRENCHED TO THE NORTH. IN ADDITION TO CONDUCIVE SST AND OHC, 
FAVORABLE UPPER-LEVEL CONDITIONS WILL PERSIST, LEADING TO RAPID 
INTENSIFICATION REACHING 115 KNOTS OVER THE NEXT 48 HOURS. 
AFTERWARD, UPPER-LEVEL CONDITIONS ARE EXPECTED TO DECREASE, SLOWING 
DOWN THE INTENSITY. DESPITE THE MARGINAL UPPER-LEVEL CONDITIONS, 
FAVORABLE ENVIRONMENT WILL CONTINUE TO FURTHER INTENSIFY CHAN-HOM 
LEADING TO A PEAK INTENSITY OF 130 KNOTS.
   C. IN THE EXTENDED TAUS, TS 09W WILL CONTINUE TO TRACK 
NORTHWESTWARD UNDER THE INFLUENCE OF THE DOMINANT STEERING STR. THE 
COMBINED EFFECT OF LIMITED UPPER-LEVEL DIVERGENCE, LOWER OHC VALUE 
AND COOLER SST WILL BEGIN TO WEAKEN THE SYSTEM AS IT APPROACH THE 
EASTERN COAST OF CHINA. WITH THE EXCEPTION OF NAVGEM WHICH REMAINS 
THE SOLE OUTLIER, DYNAMIC MODEL GUIDANCE CONTINUES TO INDICATE GOOD 
AGREEMENT. DUE TO THE TIGHT GROUPING AMONG AVAILABLE TRACKERS, THE 
JTWC TRACK FORECAST CONFIDENCE LEVEL REMAINS HIGH WHICH IS 
POSITIONED CLOSE TO MULTI-MODEL CONSENSUS.//
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