WTPN31 PGTW 171500 1. TROPICAL DEPRESSION 21W WARNING NR 003 02 ACTIVE TROPICAL CYCLONES IN NORTHWESTPAC MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE --- WARNING POSITION: 171200Z1 --- NEAR 23.7N2 140.1E6 MOVEMENT PAST SIX HOURS - 360 DEGREES AT 07 KTS POSITION ACCURATE TO WITHIN 060 NM POSITION BASED ON CENTER LOCATED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT REPEAT POSIT: 23.7N2 140.1E6 --- FORECASTS: 12 HRS, VALID AT: 180000Z9 --- 25.4N1 139.9E2 MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT VECTOR TO 24 HR POSIT: 350 DEG/ 08 KTS --- 24 HRS, VALID AT: 181200Z2 --- 27.0N9 139.6E9 MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT RADIUS OF 035 KT WINDS - 045 NM NORTHEAST QUADRANT 045 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 345 DEG/ 10 KTS --- 36 HRS, VALID AT: 190000Z0 --- 29.0N1 139.0E3 MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT RADIUS OF 035 KT WINDS - 065 NM NORTHEAST QUADRANT 065 NM SOUTHEAST QUADRANT 055 NM SOUTHWEST QUADRANT 055 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 350 DEG/ 09 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 191200Z3 --- 30.7N0 138.6E8 MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT RADIUS OF 050 KT WINDS - 040 NM RADIUS OF 035 KT WINDS - 095 NM NORTHEAST QUADRANT 095 NM SOUTHEAST QUADRANT 080 NM SOUTHWEST QUADRANT 080 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 005 DEG/ 07 KTS --- 72 HRS, VALID AT: 201200Z5 --- 33.4N0 138.9E1 MAX SUSTAINED WINDS - 085 KT, GUSTS 105 KT RADIUS OF 050 KT WINDS - 065 NM NORTHEAST QUADRANT 065 NM SOUTHEAST QUADRANT 050 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT RADIUS OF 035 KT WINDS - 130 NM NORTHEAST QUADRANT OVER WATER 130 NM SOUTHEAST QUADRANT 105 NM SOUTHWEST QUADRANT 105 NM NORTHWEST QUADRANT --- REMARKS: 171500Z4 POSITION NEAR 24.1N7 140.0E5. TROPICAL DEPRESSION (TD) 21W, LOCATED APPROXIMATELY 90 NM SOUTHWEST OF IWO JIMA, HAS TRACKED NORTHWARD AT 07 KNOTS DURING THE PAST SIX HOURS. THE WARNING POSITION IS BASED ON 171130Z3 INFRARED SATELLITE IMAGERY. THE INITIAL INTENSITY IS BASED ON CURRENT INTENSITY ESTIMATES OF 25 AND 30 KNOTS. A 170820Z8 SPECIAL SENSOR MICROWAVE IMAGER (SSM/I) PASS REVEALED DISTINCT RAINBANDS AND A MORE SYMMETRIC BUT PARTIALLY EXPOSED LOW-LEVEL CIRCULATION CENTER ON THE NORTHERN EDGE OF THE DEEP CONVECTION. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 171200Z1 IS 12 FEET. REFER TO WWPW31 RJTX FOR ADDITIONAL SEA HEIGHT INFORMATION. NEXT WARNINGS AT 172100Z1, 180300Z2, 180900Z8 AND 181500Z5. REFER TO TROPICAL STORM 20W (NARI) WARNINGS (WTPN32 PGTW) FOR SIX-HOURLY UPDATES.// BT #XXXX NNNN