WTXS32 PGTW 121500 2004072 1353 SUBJ/TROPICAL CYCLONE WARNING// RMKS/ IMMEDIATE DELIVERY REQ TO AMEMBASSY PORT LOUIS 1. TROPICAL CYCLONE 17S (NICKY-HELMA) WARNING NR 009 01 ACTIVE TROPICAL CYCLONES IN SOUTHIO MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE --- WARNING POSITION: 121200Z6 --- NEAR 19.8S8 85.6E9 MOVEMENT PAST SIX HOURS - 255 DEGREES AT 07 KTS POSITION ACCURATE TO WITHIN 060 NM POSITION BASED ON CENTER LOCATED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT RADIUS OF 050 KT WINDS - 020 NM NORTHEAST QUADRANT 030 NM SOUTHEAST QUADRANT 030 NM SOUTHWEST QUADRANT 020 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 060 NM NORTHEAST QUADRANT 110 NM SOUTHEAST QUADRANT 110 NM SOUTHWEST QUADRANT 060 NM NORTHWEST QUADRANT REPEAT POSIT: 19.8S8 85.6E9 --- FORECASTS: 12 HRS, VALID AT: 130000Z4 --- 21.0S3 84.7E9 MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT 100 NM SOUTHEAST QUADRANT 100 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 200 DEG/ 09 KTS --- 24 HRS, VALID AT: 131200Z7 --- 22.7S1 84.1E3 MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT RADIUS OF 034 KT WINDS - 040 NM NORTHEAST QUADRANT 070 NM SOUTHEAST QUADRANT 070 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 190 DEG/ 09 KTS --- 36 HRS, VALID AT: 140000Z5 --- 24.4S0 83.8E9 MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER VECTOR TO 48 HR POSIT: 200 DEG/ 09 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 141200Z8 --- 26.0S8 83.1E2 MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER --- REMARKS: 121500Z9 POSITION NEAR 20.1S3 85.4E7. TROPICAL CYCLONE (TC) 17S (NICKY-HELMA), LOCATED APPROXIMATELY 800 NM SOUTHWEST OF THE COCOS ISLANDS, HAS TRACKED WEST- SOUTHWESTWARD AT 07 KNOTS OVER THE PAST SIX HOURS. THE WARNING POSITION IS BASED ON 121130Z8 ENHANCED INFRARED SATELLITE IMAGERY. THE WARNING INTENSITY IS BASED ON SATELLITE CURRENT INTENSITY ESTIMATES OF 55, 65 AND 77 KNOTS. EARLIER VISIBLE SATELLITE IMAGERY REVEALED THE LOW LEVEL CIRCULATION CENTER (LLCC) EXPOSED ON THE NORTHWESTERN EDGE OF THE DEEP CONVECTION. THE SYSTEM IS FORECAST TO CONTINUE TRACKING POLEWARD ALONG THE WESTERN PERIPHERY OF A LOW TO MID LEVEL STEERING RIDGE TO THE EAST. TC 17S IS EXPECTED TO WEAKEN RAPIDLY AND DISSIPATE BY TAU 48 AS INCREASED WESTERLY SHEAR KEEPS THE LLCC FROM RE- COUPLING WITH THE DEEP CONVECTION. THE AVAILABLE DYNAMIC AIDS CONSISTING OF NOGAPS, WBAR, EGRR, GFDN, AND NCEP GFS ARE IN GOOD AGREEMENT WITH THIS SCENARIO. THIS FORECAST IS BASED ON A CONSENSUS OF ALL AVAILABLE AIDS. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 121200Z6 IS 18 FEET. NEXT WARNINGS AT 130300Z7 AND 131500Z0.// wxtlist.k: done