WDPN32 PGTW 250900 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 21W (MOLAVE) WARNING NR 006// RMKS/ 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL STORM (TS) 21W (MOLAVE), LOCATED APPROXIMATELY 238 NM EAST-SOUTHEAST OF MANILA, PHILIPPINES, HAS TRACKED WESTWARD AT 14 KNOTS (KTS) OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY INDICATES A RAPIDLY CONSOLIDATING SYSTEM WITH TIGHTLY-CURVED BANDING WRAPPING INTO A DEFINED LOW LEVEL CIRCULATION CENTER (LLCC). A 250525Z GMI 89 GHZ MICROWAVE IMAGE SHOWS CONVECTIVE BANDING WRAPPING TIGHTLY INTO THE CLEARLY-DEFINED LLCC; THE 37 GHZ IMAGE DEPICTS A SYMMETRIC MICROWAVE EYE FEATURE, SUPPORTING THE INITIAL POSITION WITH GOOD CONFIDENCE. THE INITIAL INTENSITY IS ASSESSED AT 60 KTS HEDGED BETWEEN DVORAK CURRENT INTENSITY ESTIMATES OF T3.5 (55 KTS, RJTD) AND T4.0 (65 KTS, PGTW/KNES). FURTHERMORE, A 250610Z ADVANCED DVORAK TECHNIQUE ESTIMATE OF T3.5 (55 KTS) AND A 250340Z SATCON ESTIMATE OF 63 KTS LEND CONFIDENCE TO THIS INTENSITY. ENVIRONMENTAL ANALYSIS REVEALS EXCELLENT EQUATORWARD OUTFLOW AND IMPROVING POLEWARD OUTFLOW, LOW TO MODERATE (15-20 KTS) VERTICAL WIND SHEAR, AND WARM (29-30 CELSIUS) SEA SURFACE TEMPERATURES (SST) CONTRIBUTING TO AN OVERALL FAVORABLE ENVIRONMENT FOR CONTINUED DEVELOPMENT. TS 21W IS TRACKING WESTWARD UNDER THE STEERING INFLUENCE OF A SUBTROPICAL RIDGE (STR) POSITIONED TO THE NORTHEAST WITH AN EXTENSION TO THE NORTH. 3. FORECAST REASONING. A. THERE IS NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TS 21W IS EXPECTED TO CONTINUE INTENSIFYING AS IT TRACKS GENERALLY WESTWARD ALONG THE PERIPHERY OF THE STR. AS FAVORABLE CONDITIONS PERSIST, THE SYSTEM SHOULD INTENSIFY TO 65 KTS PRIOR TO MAKING LANDFALL OVER THE EASTERN PHILIPPINES NEAR TAU 06. AS IT TRANSITS OVER THE INNER SEAS SOUTH OF LUZON, THE SYSTEM SHOULD MAINTAIN INTENSITY UNTIL THE SYSTEM RE-EMERGES OVER THE SOUTH CHINA SEA WHERE IT IS EXPECTED TO RE-INTENSIFY. TS 21W IS EXPECTED TO INTENSIFY TO PEAK AT 85 KTS BY TAU 60 AND THEN GRADUALLY WEAKEN AS IT APPROACHES THE COAST. NUMERICAL GUIDANCE IS IN GOOD AGREEMENT THROUGH TAU 72 WITH A 112 NM SPREAD IN SOLUTIONS AT TAU 72. CONSEQUENTLY, THERE IS HIGH CONFIDENCE IN THIS PHASE OF THE FORECAST. C. SHORTLY AFTER TAU 72, NUMERICAL GUIDANCE DIVERGES SLIGHTLY AS THE SYSTEM MAKES LANDFALL OVER CENTRAL VIETNAM. TS 21W WILL WEAKEN SIGNIFICANTLY AS IT TRACKS INLAND OVER RUGGED TERRAIN. DUE TO THE TIGHTER AGREEMENT BETWEEN THE MODELS, THERE IS OVERALL HIGH CONFIDENCE IN THE JTWC FORECAST TRACK.// NNNN