WTPS31 PGTW 240900 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 11P (WINSTON) WARNING NR 045// RMKS/ 1. TROPICAL CYCLONE 11P (WINSTON) WARNING NR 045 01 ACTIVE TROPICAL CYCLONE IN SOUTHPAC MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 240600Z --- NEAR 23.5S 174.1E MOVEMENT PAST SIX HOURS - 195 DEGREES AT 08 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 WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 135 NM NORTHEAST QUADRANT 210 NM SOUTHEAST QUADRANT 145 NM SOUTHWEST QUADRANT 100 NM NORTHWEST QUADRANT REPEAT POSIT: 23.5S 174.1E --- FORECASTS: 12 HRS, VALID AT: 241800Z --- 25.0S 172.4E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 140 NM NORTHEAST QUADRANT 220 NM SOUTHEAST QUADRANT 165 NM SOUTHWEST QUADRANT 110 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 245 DEG/ 15 KTS --- 24 HRS, VALID AT: 250600Z --- 26.1S 169.4E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY BECOMING SUBTROPICAL VECTOR TO 36 HR POSIT: 255 DEG/ 17 KTS --- 36 HRS, VALID AT: 251800Z --- 26.9S 165.6E MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY SUBTROPICAL --- REMARKS: 240900Z POSITION NEAR 23.9S 173.7E. TROPICAL CYCLONE (TC) 11P (WINSTON), LOCATED APPROXIMATELY 404 NM SOUTHWEST OF SUVA, FIJI, HAS TRACKED SOUTH-SOUTHWESTWARD AT 08 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS AN EXPOSED, BROAD LOW-LEVEL CIRCULATION CENTER WITH DEEP CONVECTION SHEARED TO THE SOUTH. A 240439Z SSMIS 91 GHZ IMAGE REVEALS SHALLOW BANDING WRAPPING AROUND A DEFINED BUT BROAD CENTER, WHICH PROVIDES GOOD CONFIDENCE IN THE CURRENT POSITION. THE INITIAL INTENSITY IS ASSESSED AT 50 KNOTS, HEDGED SLIGHTLY HIGHER THAN THE PGTW DVORAK CURRENT INTENSITY ESTIMATE OF 3.0 (45 KNOTS), BASED ON RECENT ASCAT DATA. UPPER-LEVEL ANALYSIS SHOWS AN UNFAVORABLE ENVIRONMENT WITH STRONG (30 TO 40 KNOTS) VERTICAL WIND SHEAR (VWS). TC 11P IS TRACKING ALONG THE WESTERN PERIPHERY OF THE SUBTROPICAL RIDGE (STR) AND IS FORECAST TO TURN SOUTHWESTWARD TO WEST- SOUTHWESTWARD AS IT TRANSITIONS TO THE STEERING INFLUENCE OF A BUILDING STR TO THE SOUTH. TC 11P IS EXPECTED TO CONTINUE WEAKENING AS IT ENCOUNTERS INCREASING VWS AND COOLER SST. NEAR TAU 24, THE SYSTEM WILL BEGIN TO INTERACT WITH AN UPPER-LEVEL SUBTROPICAL LOW. BY TAU 36, 11P WILL TRANSITION FULLY INTO A SUBTROPICAL LOW BUT IS EXPECTED TO MAINTAIN GALE-FORCE WINDS. DYNAMIC MODEL GUIDANCE REMAINS IN GOOD AGREEMENT, THEREFORE, THERE IS HIGH CONFIDENCE IN THE JTWC FORECAST TRACK. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 240600Z IS 17 FEET. NEXT WARNINGS AT 241500Z, 242100Z, 250300Z AND 250900Z.//