WTXS51 PGTW 270300 WARNING ATCG MIL 17S SIO 170427024005 2017042700 17S SEVENTEEN 001 01 225 08 SATL 020 T000 096S 1302E 035 R034 045 NE QD 065 SE QD 060 SW QD 040 NW QD T012 102S 1289E 040 R034 050 NE QD 105 SE QD 095 SW QD 040 NW QD T024 108S 1275E 045 R034 045 NE QD 110 SE QD 090 SW QD 040 NW QD T036 116S 1259E 045 R034 015 NE QD 110 SE QD 050 SW QD 020 NW QD T048 122S 1246E 040 R034 015 NE QD 085 SE QD 050 SW QD 020 NW QD T072 130S 1226E 035 R034 015 NE QD 065 SE QD 035 SW QD 020 NW QD T096 134S 1211E 030 AMP 072HR DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER 096HR DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER SUBJ: TROPICAL CYCLONE 17S (SEVENTEEN) WARNING NR 001 1. TROPICAL CYCLONE 17S (SEVENTEEN) WARNING NR 001 01 ACTIVE TROPICAL CYCLONE IN SOUTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 270000Z --- NEAR 9.6S 130.2E MOVEMENT PAST SIX HOURS - 225 DEGREES AT 08 KTS POSITION ACCURATE TO WITHIN 020 NM POSITION BASED ON CENTER LOCATED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 045 NM NORTHEAST QUADRANT 065 NM SOUTHEAST QUADRANT 060 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT REPEAT POSIT: 9.6S 130.2E --- FORECASTS: 12 HRS, VALID AT: 271200Z --- 10.2S 128.9E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT 105 NM SOUTHEAST QUADRANT 095 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 245 DEG/ 08 KTS --- 24 HRS, VALID AT: 280000Z --- 10.8S 127.5E MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 045 NM NORTHEAST QUADRANT 110 NM SOUTHEAST QUADRANT 090 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 245 DEG/ 09 KTS --- 36 HRS, VALID AT: 281200Z --- 11.6S 125.9E MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 015 NM NORTHEAST QUADRANT 110 NM SOUTHEAST QUADRANT 050 NM SOUTHWEST QUADRANT 020 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 245 DEG/ 07 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 290000Z --- 12.2S 124.6E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 015 NM NORTHEAST QUADRANT 085 NM SOUTHEAST QUADRANT 050 NM SOUTHWEST QUADRANT 020 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 245 DEG/ 05 KTS --- 72 HRS, VALID AT: 300000Z --- 13.0S 122.6E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER RADIUS OF 034 KT WINDS - 015 NM NORTHEAST QUADRANT 065 NM SOUTHEAST QUADRANT 035 NM SOUTHWEST QUADRANT 020 NM NORTHWEST QUADRANT VECTOR TO 96 HR POSIT: 255 DEG/ 04 KTS --- LONG RANGE OUTLOOK: --- 96 HRS, VALID AT: 010000Z --- 13.4S 121.1E MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER --- REMARKS: 270300Z POSITION NEAR 9.7S 129.9E. TROPICAL CYCLONE (TS) 17S (SEVENTEEN), LOCATED APPROXIMATELY 179 NM NORTH-NORTHWEST OF DARWIN, AUSTRALIA, HAS TRACKED SOUTHWESTWARD AT 08 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS A PARTIALLY EXPOSED LOW LEVEL CIRCULATION CENTER (LLCC) WITH DEEP FLARING CONVECTION ALONG THE SOUTHERN PERIPHERY. A 270102Z ASCAT BULLSEYE SHOWS A DEFINED LLCC WITH 35 KNOT WINDS ALONG THE SOUTHERN SIDE WRAPPING INTO THE CENTER. THE CURRENT POSITION AND INTENSITY ARE BASED ON THE SCATTEROMETER PASS WITH HIGH CONFIDENCE. ENVIRONMENTAL CONDITIONS ARE FAVORABLE WITH LOW TO MODERATE VERTICAL WIND SHEAR, STRONG DIVERGENT OUTFLOW AND WARM SEA SURFACE TEMPERATURES. TS 17S IS TRACKING ALONG THE NORTHERN PERIPHERY OF AN EXTENSION OF THE SUB-TROPICAL RIDGE LOCATED TO THE EAST. THE FAVORABLE ENVIRONMENT WILL SUPPORT A PERIOD OF INTENSIFICATION OVER THE NEXT 24 HOURS AS THE CYCLONE TRACKS WESTWARD. AFTERWARDS, INCREASING VWS WILL BEGIN TO WEAKEN THE CYCLONE AND LEAD TO ITS COMPLETE DISSIPATION BY THE END OF THE FORECAST PERIOD. AVAILABLE MODEL GUIDANCE IS IN PRETTY GOOD AGREEMENT OVER THE FIRST 36 HOURS BUT BEGIN TO DIVERGE AS THE CYCLONE WEAKENS. THIS DIVERGENCE IN GUIDANCE LENDS LOW CONFIDENCE IN THE JTWC FORECAST TRACK. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 270000Z IS 10 FEET. NEXT WARNINGS AT 271500Z AND 280300Z. THIS CANCELS AND SUPERSEDES REF A (WTXS21 PGTW 260300).// 1717042506 75S1332E 20 1717042512 75S1329E 20 1717042518 77S1325E 25 1717042600 79S1322E 30 1717042606 81S1319E 30 1717042612 85S1313E 30 1717042618 90S1308E 30 1717042700 96S1302E 35