WDPN31 PGTW 281500 MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 10W (NOCK-TEN)// WARNING NR 16// RMKS/ 1. FOR METEOROLOGISTS. 2. 12 HOUR SUMMARY AND ANALYSIS. A. TROPICAL STORM 10W (NOCK-TEN), LOCATED APPROXIMATELY 460 NM EAST-SOUTHEAST OF HANOI, VIETNAM, TRACKED WESTWARD AT 12 KNOTS OVER THE PAST SIX HOURS. ANIMATED INFRARED SATELLITE IMAGERY SHOWS THAT CENTRAL CONVECTION HAS SLIGHTLY DEEPENED AS THE FEEDER BANDS SLOWLY REORGANIZED. THE INITIAL POSITION IS BASED ON THE ABOVE ANIMATION AND EXTRAPOLATED FROM A 281050Z SSMIS MICROWAVE IMAGE. THE INITIIAL INTENSITY IS BASED ON A DVORAK ESTIMATE OF 55 KNOTS FROM PGTW AND RJTD. UPPER LEVEL ANALYSIS INDICATES THE SYSTEM IS DIRECTLY UNDER A RIDGE AXIS IN AN AREA OF LOW (05-10 KT) VERTICAL WIND SHEAR (VWS). THE CYCLONE IS BEING STEERED BY A LOW- TO MODERATE SUBTROPOICAL RIDGE CENTERED OVER EASTERN CHINA. . 3. FORECAST REASONING. A. NO CHANGE TO FORECAST PHILOSOPHY. B. TS 10W IS EXPECTED TO CONTINUE ALONG THE AFOREMENTIONED TRACK AND INTENSIFY SLIGHTLY DUE TO CONTINUED FAVORABLE CONDITIONS - WARM SEA SURFACE TEMPERATURES (SST) AND LOW VWS. IT WILL MAKE LANDFALL INTO HAINAN BEFORE TAU 24, WEAKEN DUE TO TOPOGRAPHICAL EFFECTS, THEN EXIT INTO THE GULF OF TONKIN. RELATIVELY WARMER SST'S IN THE GULF WILL FUEL A SLIGHT REINTENSIFICATION BEFORE MAKING A FINAL LANDFALL IN VIETNAM, SOUTH OF HANOI BY TAU 60. C. AFTER TAU 72, TS 10W WILL DISSIPATE AS A SIGNIFICANT TROPICAL CYCLONE JUST NORTH OF VIENTIANE, LAOS. THE AVAILABLE NUMERICAL GUIDANCE IS IN TIGHT AGREEMENT. THIS TRACK FORECAST IS SLIGHTLY FASTER THAN CONSENSUS AFTER TAU 36 TO COMPENSATE SLOWED STORM MOTION OVER HAINAN.// NNNN