WDPN33 PGTW 190300 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 11W (DIANMU) WARNING NR 05// RMKS// 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL STORM (TS) 11W (DIANMU), LOCATED APPROXIMATELY 107 NM EAST-SOUTHEAST OF HANOI, VIETNAM, HAS TRACKED WEST-SOUTHWESTWARD AT 08 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS INCREASED CONVECTION ASSOCIATED WITH A STRONGER LOW LEVEL CIRCULATION CENTER AS SEEN IN AN 182104Z SSMIS 37GHZ IMAGE WITH A COMPACT MICROWAVE EYE FEATURE. THE INITIAL POSITION IS BASED ON THE MICROWAVE EYE FEATURE WITH HIGH CONFIDENCE. THE CURRENT INTENSITY HAS BEEN INCREASED ABOVE DVORAK INTENSITY ESTIMATES BASED ON THE SIGNIFICANT MICROWAVE IMPROVEMENT. ENVIRONMENTAL CONDITIONS ARE IMPROVING WITH LOW TO MARGINAL VERTICAL WIND SHEAR BEING PARTIALLY OFFSET BY A STRONG EQUATORWARD OUTFLOW CHANNEL. ADDITIONALLY, VERY WARM SEA SURFACE TEMPERATURES NEAR 30 TO 31 CELSIUS IN THE GULF OF TONKIN ARE PROVIDING SUFFICIENT FUEL FOR INTENSIFICATION. TS 11W IS CURRENTLY TRACKING WESTWARD ALONG THE SOUTHERN PERIPHERY OF A DEEP- LAYERED SUBTROPICAL RIDGE ANCHORED OVER SOUTHERN CHINA. 3. FORECAST REASONING. A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TS 11W WILL CONTINUE TRACKING WESTWARD ALONG THE SOUTHERN PERIPHERY OF THE STEERING RIDGE, MAKING LANDFALL OVER NORTHERN VIETNAM IN THE NEXT SIX HOURS. EXPECT SOME ADDITIONAL INTENSIFICATION WHILE THE SYSTEM REMAINS OVER WARM WATER PRIOR TO LANDFALL. BEYOND TAU 12, TS DIANMU WILL MOVE FURTHER INLAND AND SLOWLY DISSIPATE BY THE END OF THE FORECAST PERIOD. DYNAMIC MODEL GUIDANCE REMAINS IN TIGHT AGREEMENT, LENDING HIGH CONFIDENCE TO THE FORECAST TRACK./=