WTPN31 PGTW 180900 1. TROPICAL STORM 20W (VONGFONG) WARNING NR 012 02 ACTIVE TROPICAL CYCLONES IN NORTHWESTPAC MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE --- WARNING POSITION: 180600Z5 --- NEAR 16.6N3 112.2E6 MOVEMENT PAST SIX HOURS - 285 DEGREES AT 08 KTS POSITION ACCURATE TO WITHIN 040 NM POSITION BASED ON CENTER LOCATED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT REPEAT POSIT: 16.6N3 112.2E6 --- FORECASTS: 12 HRS, VALID AT: 181800Z8 --- 17.4N2 111.8E1 MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT VECTOR TO 24 HR POSIT: 350 DEG/ 05 KTS --- 24 HRS, VALID AT: 190600Z6 --- 18.4N3 111.6E9 MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 350 DEG/ 08 KTS --- 36 HRS, VALID AT: 191800Z9 --- 19.9N9 111.3E6 MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT RADIUS OF 034 KT WINDS - 055 NM NORTHEAST QUADRANT 045 NM SOUTHEAST QUADRANT 045 NM SOUTHWEST QUADRANT OVER WATER 055 NM NORTHWEST QUADRANT OVER WATER VECTOR TO 48 HR POSIT: 340 DEG/ 07 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 200600Z8 --- 21.2N5 110.8E0 MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT RADIUS OF 034 KT WINDS - 055 NM NORTHEAST QUADRANT OVER WATER 045 NM SOUTHEAST QUADRANT 045 NM SOUTHWEST QUADRANT 055 NM NORTHWEST QUADRANT OVER WATER VECTOR TO 72 HR POSIT: 320 DEG/ 08 KTS --- 72 HRS, VALID AT: 210600Z9 --- 23.7N2 108.6E5 MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND --- REMARKS: 180900Z8 POSITION NEAR 16.8N5 112.1E5. TROPICAL STORM 20W (VONGFONG), LOCATED APPROXIMATELY 355 NM SOUTH- SOUTHWEST OF HONG KONG, CHINA, HAS TRACKED WEST-NORTHWESTWARD AT 08 KNOTS OVER THE PAST 6 HOURS. THE WARNING POSITION IS BASED ON 180530Z7 MULTISPECTRAL SATELLITE IMAGERY AND SYNOPTIC OBSERVATIONS. THE WARNING INTENSITY IS BASED ON SATELLITE CURRENT INTENSITY ESTIMATES OF 30 AND 35 KNOTS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY INDICATES THAT DEEP CONVECTION HAS DEVELOPED OVER THE LOW LEVEL CIRCULATION CENTER OVER THE PAST 6 HOURS. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 180600Z5 IS 18 FEET. REFER TO WWPW30 RJTX FOR ADDITIONAL SEA HEIGHT INFORMATION. NEXT WARNINGS AT 181500Z5, 182100Z2, 190300Z3 AND 190900Z9. REFER TO TYPHOON 19W (PHANFONE) WARNINGS (WTPN32 PGTW) FOR SIX-HOURLY UPDATES.// NNNN