WDPN31 PGTW 160300 MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 07W WARNING NR 04// RMKS/ 1. FOR METEOROLOGISTS. 2. 12 HOUR SUMMARY AND ANALYSIS. A. TROPICAL STORM (TS) 07W (SEVEN) HAS CONTINUED TO TRACK NORTH- WESTWARD AT 10 KNOTS OVER THE PAST SIX HOURS AND HAS INCREASED IN INTENSITY TO A WEAK TROPICAL STORM. RECENT ANIMATED MULTISPECTRAL IMAGERY SHOWS DECENT CONVECTION WRAPPING INTO THE STORM CENTER AND ANIMATED WATER VAPOR IMAGERY SHOWS DEEP CONVECTION TO THE WEST OF THE SYSTEM AS WELL AS INDICATIONS OF POLEWARD OUTFLOW INTO A TROPICAL UPPER TROPOSPHERIC TROUGH SITUATED TO THE NORTHEAST. CURRENT POSITION AND INTENSITY ARE BASED ON A 152324Z 91 GHZ SSMI MICROWAVE IMAGE AND THE PGTW 152330Z FIX. TS 07W IS TRACKING ALONG THE SOUTHWESTERN PERIPHERY OF A LOW- TO MID-LEVEL ANTICYCLONE RIDGING INTO CHINA FROM THE EAST. 3. FORECAST REASONING. A. THE FORECAST REASONING HAS NOT CHANGED SINCE THE PREVIOUS PROGNOSTIC REASONING BULLETIN. B. TD 07W IS EXPECTED TO CONTINUE TRACKING NORTHWESTWARD ALONG THE SOUTHWESTERN PERIPHERY OF THE SUBTROPICAL RIDGE EXTENDING INTO CHINA DESCRIBED IN PARA 2.A. THE SYSTEM WILL MAINTAIN AS A TROPICAL STORM AS IT PASSES THROUGH THE LUZON STRAIT INTO THE SOUTH CHINA SEA AND WILL BE SUSTAINED BY FAVORABLE UPPER-LEVEL OUTFLOW AND ALONG- TRACK SEA SURFACE TEMPERATURES AND OCEAN HEAT CONTENT. MODEL AIDS ARE IN GOOD AGREEMENT WITH THIS SCENARIO WITH THE EXCEPTION OF THE NOGAPS AND JGSM TRACKERS WHICH ARE OPTING FOR A TRACK THROUGH TAIWAN INTO THE RIDGE. BY TAU 48, THE SYSTEM WILL START TO ENCOUNTER UNFAVORABLE NORTHEASTERLY VERTICAL WIND SHEAR AND WILL START TO WEAKEN IN INTENSITY PRIOR TO MAKING LANDFALL. C. AFTER TAU 72, TS 07W WILL MAKE LANDFALL IN THE VICINITY OF HONG KONG AND DISSIPATE OVER LAND BY TAU 96. FORECAST TEAM: CHARLIE// NNNN