WTPS31 PGTW 180300 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 11P (WINSTON) WARNING NR 020// RMKS/ 1. TROPICAL CYCLONE 11P (WINSTON) WARNING NR 020 01 ACTIVE TROPICAL CYCLONE IN SOUTHPAC MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 180000Z --- NEAR 17.1S 171.1W MOVEMENT PAST SIX HOURS - 270 DEGREES AT 02 KTS POSITION ACCURATE TO WITHIN 030 NM POSITION BASED ON CENTER LOCATED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 105 KT, GUSTS 130 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 015 NM NORTHEAST QUADRANT 030 NM SOUTHEAST QUADRANT 010 NM SOUTHWEST QUADRANT 020 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 040 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 050 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 100 NM NORTHEAST QUADRANT 120 NM SOUTHEAST QUADRANT 110 NM SOUTHWEST QUADRANT 120 NM NORTHWEST QUADRANT REPEAT POSIT: 17.1S 171.1W --- FORECASTS: 12 HRS, VALID AT: 181200Z --- 17.2S 171.4W MAX SUSTAINED WINDS - 120 KT, GUSTS 145 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 035 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 035 NM SOUTHWEST QUADRANT 035 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 060 NM NORTHEAST QUADRANT 080 NM SOUTHEAST QUADRANT 075 NM SOUTHWEST QUADRANT 055 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 120 NM NORTHEAST QUADRANT 165 NM SOUTHEAST QUADRANT 145 NM SOUTHWEST QUADRANT 115 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 265 DEG/ 04 KTS --- 24 HRS, VALID AT: 190000Z --- 17.3S 172.3W MAX SUSTAINED WINDS - 120 KT, GUSTS 145 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 035 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 035 NM SOUTHWEST QUADRANT 035 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 060 NM NORTHEAST QUADRANT 080 NM SOUTHEAST QUADRANT 075 NM SOUTHWEST QUADRANT 055 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 115 NM NORTHEAST QUADRANT 155 NM SOUTHEAST QUADRANT 135 NM SOUTHWEST QUADRANT 110 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 255 DEG/ 06 KTS --- 36 HRS, VALID AT: 191200Z --- 17.6S 173.6W MAX SUSTAINED WINDS - 115 KT, GUSTS 140 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 040 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 035 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 065 NM NORTHEAST QUADRANT 075 NM SOUTHEAST QUADRANT 070 NM SOUTHWEST QUADRANT 060 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 110 NM NORTHEAST QUADRANT 145 NM SOUTHEAST QUADRANT 130 NM SOUTHWEST QUADRANT 105 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 250 DEG/ 08 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 200000Z --- 18.1S 175.2W MAX SUSTAINED WINDS - 110 KT, GUSTS 135 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 035 NM NORTHEAST QUADRANT 035 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 045 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 055 NM NORTHEAST QUADRANT 055 NM SOUTHEAST QUADRANT 070 NM SOUTHWEST QUADRANT 075 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 110 NM NORTHEAST QUADRANT 115 NM SOUTHEAST QUADRANT 130 NM SOUTHWEST QUADRANT 130 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 250 DEG/ 07 KTS --- 72 HRS, VALID AT: 210000Z --- 19.1S 177.9W MAX SUSTAINED WINDS - 105 KT, GUSTS 130 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 - 065 NM NORTHEAST QUADRANT 075 NM SOUTHEAST QUADRANT 070 NM SOUTHWEST QUADRANT 065 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 110 NM NORTHEAST QUADRANT 135 NM SOUTHEAST QUADRANT 125 NM SOUTHWEST QUADRANT 110 NM NORTHWEST QUADRANT VECTOR TO 96 HR POSIT: 210 DEG/ 03 KTS --- LONG RANGE OUTLOOK: --- 96 HRS, VALID AT: 220000Z --- 20.0S 178.4W MAX SUSTAINED WINDS - 100 KT, GUSTS 125 KT WIND RADII VALID OVER OPEN WATER ONLY VECTOR TO 120 HR POSIT: 140 DEG/ 03 KTS --- 120 HRS, VALID AT: 230000Z --- 20.9S 177.6W MAX SUSTAINED WINDS - 095 KT, GUSTS 115 KT WIND RADII VALID OVER OPEN WATER ONLY --- REMARKS: 180300Z POSITION NEAR 17.1S 171.2W. TROPICAL CYCLONE (TC) 11P (WINSTON), LOCATED APPROXIMATELY 138 NM NORTH-NORTHWEST OF NIUE, HAS TRACKED WESTWARD AT 02 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY SHOWS DEEPENED CENTRAL CONVECTION WITH A DEVELOPING EYE, SUPPORTING THE HIGH CONFIDENCE IN THE CURRENT POSITION. THE INITIAL INTENSITY OF 105 KNOTS IS BASED ON AN OVERALL ASSESSMENT OF DVORAK INTENSITY ESTIMATES FROM ALL REPORTING AGENCIES AND THE IMPROVED STRUCTURE. UPPER-LEVEL ANALYSIS INDICATES WINSTON IS LOCATED IN A FAVORABLE ENVIRONMENT WITH LOW (10 TO 15 KNOT) VERTICAL WIND SHEAR AND GOOD POLEWARD OUTFLOW. ADDITIONALLY, SEA SURFACE TEMPERATURES (30 DEGREES CELSIUS) ARE CONDUCIVE FOR FURTHER DEVELOPMENT. FAVORABLE CONDITIONS ARE FORECAST TO PERSIST, ALLOWING STEADY INTENSIFICATION OVER THE NEXT 24 HOURS, LEADING TO A PEAK INTENSITY OF 120 KNOTS. AFTERWARD, UPPER-LEVEL CONDITIONS WILL SLOWLY DEGRADE, LEADING TO ITS WEAKENING TREND. SLOW AND/OR QUASI-STATIONARY MOVEMENT IS EXPECTED AS TC WINSTON REMAINS IN A WEAK STEERING ENVIRONMENT FOR THE NEXT 12 TO 18 HOURS. THE SYSTEM IS FORECAST TO TRACK WESTWARD AS THE STR TO THE SOUTH BECOMES DOMINANT. DUE TO SIGNIFICANT DIFFERENCES IN THE TRACKS AND TRACK SPEEDS AMONG AVAILABLE TRACKERS, THE JTWC TRACK CONFIDENCE LEVEL REMAINS LOW. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 180000Z IS 28 FEET. NEXT WARNINGS AT 180900Z, 181500Z, 182100Z AND 190300Z.//