WTPS31 PGTW 151500 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 11P (WINSTON) WARNING NR 011// RMKS/ 1. TROPICAL CYCLONE 11P (WINSTON) WARNING NR 011 01 ACTIVE TROPICAL CYCLONE IN SOUTHPAC MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 151200Z --- NEAR 20.6S 178.1W MOVEMENT PAST SIX HOURS - 050 DEGREES AT 18 KTS POSITION ACCURATE TO WITHIN 040 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 - 080 NM NORTHEAST QUADRANT 150 NM SOUTHEAST QUADRANT 095 NM SOUTHWEST QUADRANT 130 NM NORTHWEST QUADRANT REPEAT POSIT: 20.6S 178.1W --- FORECASTS: 12 HRS, VALID AT: 160000Z --- 19.3S 176.5W MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 050 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 050 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 080 NM NORTHEAST QUADRANT 150 NM SOUTHEAST QUADRANT 095 NM SOUTHWEST QUADRANT 130 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 050 DEG/ 09 KTS --- 24 HRS, VALID AT: 161200Z --- 18.1S 175.0W MAX SUSTAINED WINDS - 060 KT, GUSTS 075 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 050 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 050 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 090 NM NORTHEAST QUADRANT 150 NM SOUTHEAST QUADRANT 105 NM SOUTHWEST QUADRANT 130 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 065 DEG/ 08 KTS --- 36 HRS, VALID AT: 170000Z --- 17.4S 173.5W MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 045 NM NORTHEAST QUADRANT 045 NM SOUTHEAST QUADRANT 045 NM SOUTHWEST QUADRANT 045 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 100 NM NORTHEAST QUADRANT 150 NM SOUTHEAST QUADRANT 115 NM SOUTHWEST QUADRANT 140 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 050 DEG/ 03 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 171200Z --- 17.0S 173.0W MAX SUSTAINED WINDS - 075 KT, GUSTS 090 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 020 NM NORTHEAST QUADRANT 020 NM SOUTHEAST QUADRANT 020 NM SOUTHWEST QUADRANT 020 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 040 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 110 NM NORTHEAST QUADRANT 150 NM SOUTHEAST QUADRANT 125 NM SOUTHWEST QUADRANT 140 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 295 DEG/ 01 KTS --- 72 HRS, VALID AT: 181200Z --- 16.8S 173.5W MAX SUSTAINED WINDS - 080 KT, GUSTS 100 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 015 NM NORTHEAST QUADRANT 015 NM SOUTHEAST QUADRANT 015 NM SOUTHWEST QUADRANT 015 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 030 NM NORTHEAST QUADRANT 030 NM SOUTHEAST QUADRANT 030 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 130 NM NORTHEAST QUADRANT 170 NM SOUTHEAST QUADRANT 150 NM SOUTHWEST QUADRANT 130 NM NORTHWEST QUADRANT VECTOR TO 96 HR POSIT: 250 DEG/ 05 KTS --- LONG RANGE OUTLOOK: --- 96 HRS, VALID AT: 191200Z --- 17.4S 175.5W MAX SUSTAINED WINDS - 085 KT, GUSTS 105 KT WIND RADII VALID OVER OPEN WATER ONLY VECTOR TO 120 HR POSIT: 245 DEG/ 05 KTS --- 120 HRS, VALID AT: 201200Z --- 18.3S 177.5W MAX SUSTAINED WINDS - 085 KT, GUSTS 105 KT WIND RADII VALID OVER OPEN WATER ONLY --- REMARKS: 151500Z POSITION NEAR 20.3S 177.7W. TROPICAL CYCLONE 11P (WINSTON), LOCATED APPROXIMATELY 248 NM SOUTHEAST OF SUVA, FIJI, HAS TRACKED NORTHEASTWARD AT 18 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY REVEALS TC 11P REMAINS EMBEDDED WITHIN THE TROUGH, HOWEVER DEEP CONVECTIVE COVERAGE HAS BEGUN TO EXPAND AND CLOUD-TOPS HAVE COOLED OVER THE PAST 6-HOURS. A 151051Z GPM 36 GHZ IMAGE DEPICTS A WELL-DEFINED LOW-LEVEL CIRCULATION CENTER (LLCC) WITH TIGHTLY CURVED BANDING WRAPPING INTO THE SYSTEM. THE INITIAL POSITION IS BASED UPON A 150958Z ASCAT AMBIGUITY ANALYSIS WITH GOOD CONFIDENCE. THE INITIAL INTENSITY IS ASSESSED AT 50 KNOTS BASED UPON THE RECENT SCATTEROMETRY DATA. UPPER LEVEL ANALYSIS SHOWS A MARGINALLY- FAVORABLY ENVIRONMENT FOR DEVELOPMENT WITH GOOD OUTFLOW OFFSET BY MODERATE TO STRONG (20 TO 30 KNOTS) VERTICAL WIND SHEAR (VWS). TC WINSTON IS FORECAST TO CONTINUE TRACKING NORTHEASTWARD ALONG THE SOUTHEAST PERIPHERY OF THE STEERING RIDGE. A WEAKNESS IN THE RIDGE IS FORECAST TO FORM BETWEEN TAU 36 THROUGH TAU 72, CAUSING THE SYSTEM TO SLOW IN FORWARD SPEED, AND THEN BECOME QUASI-STATIONARY AFTER TAU 36, AS A SECONDARY RIDGE BUILDS IN FROM THE SOUTHWEST. AFTER TAU 72, TC 11P WILL BEGIN TO ACCELERATE WESTWARD AS THE RIDGE TO THE EAST STRENGTHENS AND THE RIDGE TO THE SOUTHWEST MOVES WESTWARD. TC WINSTON IS FORECAST TO GRADUALLY REGAIN INTENSITY DURING THE FORECAST PERIOD AS IT TRACKS OVER WARMER (29-30C) SSTS AND THROUGH A REGION OF DECREASING VWS. DYNAMIC MODEL GUIDANCE IS IN FAIR AGREEMENT THROUGH TAU 48, HOWEVER, SOLUTIONS BEGIN TO DIVERGE AFTER TAU 48 DUE TO HIGH UNCERTAINTY WITH THE OVERALL SYNOPTIC STEERING PATTERN. THEREFORE, THERE IS LOW CONFIDENCE IN THE JTWC FORECAST TRACK. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 151200Z IS 21 FEET. NEXT WARNINGS AT 160300Z AND 161500Z.//