MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/PROGNOSTIC REASONING FOR TROPICAL STORM 07W (SEVEN) WARNING NR 003// RMKS// 1. FOR METEOROLOGISTS. 2. 6 HOUR SUMMARY AND ANALYSIS. TROPICAL STORM 07W (SEVEN), LOCATED APPROXIMATELY 305 NM SOUTHEAST OF HONG KONG, HAS TRACKED NORTHWARD AT 09 KNOTS OVER THE PAST SIX HOURS. THE CURRENT POSITION IS SITUATED DOWNSTREAM FROM A CENTER FEATURE EVIDENT IN 092233Z SSMIS IMAGERY AND NEAR SATELLITE POSITION FIXES FROM PGTW AND RJTD. THE INTENSITY OF 35 KNOTS IS BASED ON A CONSENSUS OF RECENT SUBJECTIVE DVORAK AND AUTOMATED INTENSITY ESTIMATES FROM MULTIPLE REPORTING AGENCIES, AND A 100031Z METOP-A ASCAT PASS SHOWING AN AREA OF 35 KNOT WINDS WITHIN THE SOUTHERN PORTION OF THE LOW-LEVEL CIRCULATION. DEEP CONVECTION HAS INCREASED OVER THE CIRCULATION AND CONVECTIVE BANDING HAS BECOME MORE DEFINED OVER THE PAST SIX HOURS. TS 07W IS TRACKING POLEWARD ALONG THE WESTERN PERIPHERY OF A SUBTROPICAL STEERING RIDGE (STR) EXTENSION. THE SYSTEM IS SITUATED IN AN AREA OF MODERATE (15-20 KTS) VERTICAL WIND SHEAR AND VERY WARM (29-30C) SEA SURFACE TEMPERATURES. UPPER-LEVEL DIFFLUENCE IS LIMITED, BUT AN ANALYSIS OF SATELLITE- DERIVED ATMOSPHERIC MOTION VECTORS SUGGESTS THAT SOUTHWESTWARD OUTFLOW IS INCREASING. 3. FORECAST REASONING. A. NO CHANGE TO THE FORECAST PHILOSOPHY SINCE THE PREVIOUS PROGNOSTIC REASONING MESSAGE. B. TS 07W WILL CONTINUE TO TRACK POLEWARD ALONG THE STR THROUGH THE FORECAST PERIOD, MAKING LANDFALL IN SOUTHEASTERN CHINA JUST AFTER TAU 24. STEADY INTENSIFICATION IS ANTICIPATED PRIOR TO LANDFALL, DESPITE PERSISTENT VERTICAL WIND SHEAR, DUE TO CONTINUED PASSAGE OVER VERY WARM WATER AND INCREASING POLEWARD OUTFLOW AIDED BY AN UPPER-LEVEL TROUGH TO THE NORTHEAST. AFTER THE SYSTEM MAKES LANDFALL, IT WILL WEAKEN DUE TO THE FRICTIONAL EFFECTS OF LAND AND DISSIPATE BY TAU 48. NUMERICAL MODEL FORECASTS ARE IN GOOD AGREEMENT REGARDING THE OVERALL FORECAST SCENARIO, BUT THERE IS SOME SPREAD IN THE EXACT DIRECTION AND SPEED OF MOVEMENT. OVERALL, THERE IS FAIR CONFIDENCE IN JTWC TRACK FORECAST.// NNNN NNNN