WTPN31 PGTW 290900 1. TROPICAL STORM 11W (BOLAVEN) WARNING NR 019 02 ACTIVE TROPICAL CYCLONES IN NORTHWESTPAC MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE --- WARNING POSITION: 290600Z7 --- NEAR 29.2N3 128.7E8 MOVEMENT PAST SIX HOURS - 345 DEGREES AT 07 KTS POSITION ACCURATE TO WITHIN 060 NM POSITION BASED ON CENTER LOCATED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT RADIUS OF 035 KT WINDS - 090 NM EAST SEMICIRCLE 045 NM ELSEWHERE REPEAT POSIT: 29.2N3 128.7E8 --- FORECASTS: 12 HRS, VALID AT: 291800Z0 --- 31.1N5 128.9E0 MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT RADIUS OF 035 KT WINDS - 090 NM EAST SEMICIRCLE OVER WATER 045 NM ELSEWHERE VECTOR TO 24 HR POSIT: 005 DEG/ 11 KTS --- 24 HRS, VALID AT: 300600Z9 --- 33.3N9 129.1E3 MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT RADIUS OF 035 KT WINDS - 085 NM EAST SEMICIRCLE OVER WATER 040 NM ELSEWHERE VECTOR TO 36 HR POSIT: 020 DEG/ 11 KTS --- 36 HRS, VALID AT: 301800Z2 --- 35.3N1 129.9E1 MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT RADIUS OF 035 KT WINDS - 080 NM EAST SEMICIRCLE OVER WATER 040 NM ELSEWHERE OVER WATER VECTOR TO 48 HR POSIT: 020 DEG/ 14 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 310600Z0 --- 37.8N8 131.2E7 MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT BECOMING EXTRATROPICAL VECTOR TO 72 HR POSIT: 020 DEG/ 16 KTS --- 72 HRS, VALID AT: 010600Z7 --- 44.0N8 134.1E9 MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT BECOMING EXTRATROPICAL --- REMARKS: 290900Z0 POSITION NEAR 29.7N8 128.7E8. TROPICAL STORM (TS) 11W (BOLAVEN), LOCATED APPROXIMATELY 225 NM SOUTH-SOUTHWEST OF SASEBO, JAPAN, HAS TRACKED NORTH-NORTHWESTWARD AT 07 KNOTS DURING THE PAST 6 HOURS. THE WARNING POSITION IS BASED ON 290530Z9 VISIBLE AND INFRARED SATELLITE IMAGERY. THE WARNING INTENSITY IS BASED ON SATELLITE CURRENT INTENSITY ESTIMATES OF 35 AND 55 KNOTS, A RECENT ERS-2 SCATTEROMETER PASS, AND SYNOPTIC REPORTS. ANIMATED VISIBLE AND INFRARED SATELLITE IMAGERY DEPICTS CONVECTION CONTINUING TO PERSIST ON THE SOUTH SIDE OF A PARTIALLY- EXPOSED LOW-LEVEL CIRCULATION CENTER (LLCC) OVER THE PAST 6 HOURS. HOWEVER, IMAGERY SHOWS THAT THE CONVECTION HAS WEAKENED DURING THIS SAME TIME PERIOD. ANIMATED WATER VAPOR IMAGERY DEPICTS GOOD OUTFLOW ALOFT EXCEPT IN THE NORTHERN QUADRANT. THE UW-CIMSS ANALYSIS INDICATES MODERATE VERTICAL WIND SHEAR AND NORTHEASTERLY FLOW OVER THE SYSTEM. TS 11W IS CURRENTLY BEING STEERED SLOWLY TO THE NORTH-NORTHWEST BY THE WEAK SUBTROPICAL RIDGE TO THE NORTHEAST. AN APPROACHING MID-LATITUDE TROUGH IS EXPECTED TO ENHANCE THE WEAKNESS IN THE RIDGE, ALLOWING THE SYSTEM TO ACCELERATE NORTHWARD INITIALLY AND THEN NORTH-NORTHEASTWARD AFTER THE 24 HOUR FORECAST PERIOD. TS 11W IS FORECAST BEGIN WEAKENING AS IT TRACKS UNDER AN INCREASINGLY UNFAVORABLE ENVIRONMENT. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 290600Z7 IS 16 FEET. REFER TO WWPW30 RJTX FOR ADDITIONAL SEA HEIGHT INFORMATION. NEXT WARNINGS AT 291500Z7 (DTG 291351Z1), 292100Z4 (DTG 291951Z7), 300300Z6 (DTG 300151Z0) AND 300900Z2 (DTG 300751Z6). REFER TO TROPICAL STORM 12W (CHANCHU) WARNINGS (WTPN32 PGTW) FOR SIX-HOURLY UPDATES.// NNNN