WTPN31 PGTW 091500 1. TROPICAL STORM 28W WARNING NR 012 01 ACTIVE TROPICAL CYCLONE IN NORTHWESTPAC MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE --- WARNING POSITION: 091200Z2 --- NEAR 13.7N1 111.9E2 MOVEMENT PAST SIX HOURS - 325 DEGREES AT 11 KTS POSITION ACCURATE TO WITHIN 060 NM POSITION BASED ON CENTER LOCATED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT RADIUS OF 035 KT WINDS - 055 NM NORTHEAST SEMICIRCLE 030 NM ELSEWHERE REPEAT POSIT: 13.7N1 111.9E2 --- FORECASTS: 12 HRS, VALID AT: 100000Z1 --- 14.7N2 110.9E1 MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT RADIUS OF 035 KT WINDS - 055 NM NORTHEAST SEMICIRCLE 030 NM ELSEWHERE VECTOR TO 24 HR POSIT: 300 DEG/ 07 KTS --- 24 HRS, VALID AT: 101200Z4 --- 15.4N0 109.7E7 MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT RADIUS OF 035 KT WINDS - 060 NM NORTHEAST SEMICIRCLE 035 NM ELSEWHERE VECTOR TO 36 HR POSIT: 295 DEG/ 07 KTS --- 36 HRS, VALID AT: 110000Z2 --- 16.0N7 108.3E2 MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT RADIUS OF 035 KT WINDS - 060 NM NORTHEAST SEMICIRCLE 035 NM ELSEWHERE OVER WATER VECTOR TO 48 HR POSIT: 295 DEG/ 06 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 111200Z5 --- 16.5N2 107.1E9 MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND VECTOR TO 72 HR POSIT: 285 DEG/ 06 KTS --- 72 HRS, VALID AT: 121200Z6 --- 17.0N8 104.8E3 MAX SUSTAINED WINDS - 020 KT, GUSTS 030 KT DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND --- REMARKS: 091500Z5 POSITION NEAR 14.0N5 111.6E9. TROPICAL STORM (TS) 28W, LOCATED APPROXIMATELY 250 NM EAST-SOUTHEAST OF DA NANG, VIETNAM, HAS TRACKED NORTH-NORTHWESTWARD AT 11 KNOTS OVER THE PAST SIX HOURS. THE WARNING POSITION IS BASED ON 091130Z4 INFRARED SATELLITE IMAGERY. THE WARNING INTENSITY IS BASED ON SATELLITE CURRENT INTENSITY ESTIMATES OF 35 TO 55 KNOTS. ANIMATED INFRARED IMAGERY DEPICTS PARTIALLY EXPOSED LOW-LEVEL CIRCULATION CENTER WITH DEEP CONVECTION BEING SHEARED TO THE WEST. UW-CIMSS SHEAR ANALYSIS IS SHOWING 10 TO 20 KNOT UPPER-LEVEL EASTERLIES OVER THE REGION. SYNOPTIC DATA REVEALS THAT THE STRONGER WINDS ARE SITUATED OVER THE PERIPHERY AND TO THE SOUTH OF THE SYSTEM. THE MID- LEVEL RIDGE BUILDING OVER THE TAIWAN STRAIT IS THE DOMINANT STEERING INFLUENCE AND WILL CAUSE THE SYSTEM TO TRACK MORE NORTHWEST TO WEST THROUGH THE FORECAST PERIOD. THE SYSTEM IS FORECAST TO INTENSIFY SLIGHTLY OVER THE NEXT 24 HOURS AS THE SYSTEM TRACKS BENEATH THE UPPER LEVEL RIDGE. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 091200Z2 IS 16 FEET. REFER TO WWPW31 RJTX FOR ADDITIONAL SEA HEIGHT INFORMATION. NEXT WARNINGS AT 092100Z2 (DTG 091951Z5), 100300Z4 (DTG 100151Z8), 100900Z0 (DTG 100751Z4) AND 101500Z7 (DTG 101351Z1).// NNNN