WTPS31 PGTW 221500 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE WARNING// RMKS/ 1. TROPICAL CYCLONE 11P (WINSTON) WARNING NR 038 01 ACTIVE TROPICAL CYCLONE IN SOUTHPAC MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 221200Z --- NEAR 18.2S 172.3E MOVEMENT PAST SIX HOURS - 180 DEGREES AT 03 KTS POSITION ACCURATE TO WITHIN 020 NM POSITION BASED ON EYE FIXED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 090 KT, GUSTS 110 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 030 NM NORTHEAST QUADRANT 030 NM SOUTHEAST QUADRANT 030 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 050 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 060 NM SOUTHWEST QUADRANT 055 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 130 NM NORTHEAST QUADRANT 160 NM SOUTHEAST QUADRANT 160 NM SOUTHWEST QUADRANT 095 NM NORTHWEST QUADRANT REPEAT POSIT: 18.2S 172.3E --- FORECASTS: 12 HRS, VALID AT: 230000Z --- 19.2S 172.8E MAX SUSTAINED WINDS - 090 KT, GUSTS 110 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 040 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 045 NM SOUTHWEST QUADRANT 035 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 060 NM NORTHEAST QUADRANT 075 NM SOUTHEAST QUADRANT 075 NM SOUTHWEST QUADRANT 055 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 100 NM NORTHEAST QUADRANT 140 NM SOUTHEAST QUADRANT 140 NM SOUTHWEST QUADRANT 095 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 145 DEG/ 08 KTS --- 24 HRS, VALID AT: 231200Z --- 20.6S 173.8E MAX SUSTAINED WINDS - 085 KT, GUSTS 105 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 045 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 045 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 070 NM NORTHEAST QUADRANT 075 NM SOUTHEAST QUADRANT 070 NM SOUTHWEST QUADRANT 060 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 120 NM NORTHEAST QUADRANT 135 NM SOUTHEAST QUADRANT 130 NM SOUTHWEST QUADRANT 105 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 160 DEG/ 08 KTS --- 36 HRS, VALID AT: 240000Z --- 22.2S 174.4E MAX SUSTAINED WINDS - 080 KT, GUSTS 100 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 050 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 045 NM SOUTHWEST QUADRANT 045 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 075 NM NORTHEAST QUADRANT 075 NM SOUTHEAST QUADRANT 070 NM SOUTHWEST QUADRANT 065 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 130 NM NORTHEAST QUADRANT 130 NM SOUTHEAST QUADRANT 120 NM SOUTHWEST QUADRANT 115 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 190 DEG/ 07 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 241200Z --- 23.5S 174.1E MAX SUSTAINED WINDS - 070 KT, GUSTS 085 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 040 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 065 NM NORTHEAST QUADRANT 075 NM SOUTHEAST QUADRANT 075 NM SOUTHWEST QUADRANT 065 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 110 NM NORTHEAST QUADRANT 130 NM SOUTHEAST QUADRANT 130 NM SOUTHWEST QUADRANT 110 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 235 DEG/ 10 KTS --- 72 HRS, VALID AT: 251200Z --- 25.7S 170.5E MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT WIND RADII VALID OVER OPEN WATER ONLY BECOMING SUBTROPICAL RADIUS OF 034 KT WINDS - 110 NM NORTHEAST QUADRANT 130 NM SOUTHEAST QUADRANT 135 NM SOUTHWEST QUADRANT 110 NM NORTHWEST QUADRANT VECTOR TO 96 HR POSIT: 245 DEG/ 15 KTS --- LONG RANGE OUTLOOK: --- 96 HRS, VALID AT: 261200Z --- 28.3S 164.4E MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY SUBTROPICAL --- REMARKS: 221500Z POSITION NEAR 18.5S 172.4E. TROPICAL CYCLONE 11P (WINSTON), LOCATED APPROXIMATELY 348 NM WEST OF SUVA, FIJI, HAS TRACKED SOUTHWARD AT 03 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS A RAGGED 20NM EYE THAT HAS CHANGED LITTLE IN STRUCTURE OVER THE LAST SIX HOURS GIVING HIGH CONFIDENCE TO THE INITIAL POSITION. THE CURRENT INTENSITY IS ASSESSED TO BE 90 KNOTS WHICH IS BASED ON DVORAK ESTIMATES FROM ALL AGENCIES REPORTING CURRENT INTENSITIES OF T5.0 (90 KNOTS). SEA SURFACE TEMPERATURES ARE WARM (29 CELSIUS), AND A STRONG POLEWARD OUTFLOW CHANNEL EXISTS WHICH IS HELPING TO MAINTAIN THE CURRENT INTENSITY. HOWEVER, THE EQUATORWARD OUTFLOW CHANNEL IS SHOWING SIGNS OF WEAKENING DUE TO CONVERGENCE OBSERVED NORTH OF THE CYCLONE, EVIDENT ON RECENT WATER VAPOR IMAGERY. THE CIMSS MICROWAVE TPW LOOP ALSO INDICATES A BAND OF DRY AIR CURRENTLY BEING ENTRAINED INTO THE CYCLONE HINDERING FURTHER INTENSIFICATION. WINSTON SHOULD MAINTAIN ITS CURRENT INTENSITY FOR THE NEXT 12 HOURS, BEFORE WEAKENING SIGNIFICANTLY DUE TO THE DISRUPTION OF THE EQUATORWARD EXHAUST CHANNEL AND INCREASED VERTICAL WIND SHEAR ASSOCIATED WITH A DEEPENING TROUGH TO THE WEST. THE CURRENT MOVEMENT IS QUASI-STATIONARY AS THE PRIMARY STEERING MECHANISM IS SHIFTING FROM A RIDGE RETROGRADING WESTWARD TO A RIDGE BUILDING IN TO THE EAST. TC WINSTON WILL SOON ACCELERATE ALONG A SOUTHEASTWARD TRACK, GUIDED BY THE BUILDING RIDGE TO THE EAST. BY TAU 72, AS THE SYSTEM WEAKENS, THE DOMINANT STEERING MECHANISM WILL SHIFT TO A LOW TO MID-LEVEL RIDGE TO THE SOUTH WHICH WILL STEER TC WINSTON WESTWARD UNDER AN UPPER-LEVEL TROUGH. THE SUBSIDENCE ASSOCIATED WITH THE TROUGH AND SSTS DROPPING BELOW 26 CELSIUS WILL BEGIN SUBTROPICAL TRANSITION INTO A COLD CORE SYSTEM. TC WINSTON IS FORECAST TO COMPLETE SUBTROPICAL TRANSITION BY TAU 96. DYNAMIC MODEL GUIDANCE IS IN GOOD AGREEMENT PROVIDING HIGH CONFIDENCE TO THE JTWC FORECAST TRACK. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 221200Z IS 34 FEET. NEXT WARNINGS AT 222100Z, 230300Z, 230900Z AND 231500Z.//