WTPS31 PGTW 160300 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE WARNING// RMKS/ 1. TROPICAL CYCLONE 11P (WINSTON) WARNING NR 012 01 ACTIVE TROPICAL CYCLONE IN SOUTHPAC MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 160000Z --- NEAR 19.2S 175.5W MOVEMENT PAST SIX HOURS - 060 DEGREES AT 13 KTS POSITION ACCURATE TO WITHIN 060 NM POSITION BASED ON CENTER LOCATED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 160 NM NORTHEAST QUADRANT 170 NM SOUTHEAST QUADRANT 095 NM SOUTHWEST QUADRANT 160 NM NORTHWEST QUADRANT REPEAT POSIT: 19.2S 175.5W --- FORECASTS: 12 HRS, VALID AT: 161200Z --- 18.1S 173.6W MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 150 NM NORTHEAST QUADRANT 150 NM SOUTHEAST QUADRANT 115 NM SOUTHWEST QUADRANT 115 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 070 DEG/ 06 KTS --- 24 HRS, VALID AT: 170000Z --- 17.7S 172.4W 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 - 150 NM NORTHEAST QUADRANT 150 NM SOUTHEAST QUADRANT 105 NM SOUTHWEST QUADRANT 105 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 080 DEG/ 05 KTS --- 36 HRS, VALID AT: 171200Z --- 17.5S 171.3W MAX SUSTAINED WINDS - 060 KT, GUSTS 075 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 045 NM NORTHEAST QUADRANT 045 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 145 NM NORTHEAST QUADRANT 145 NM SOUTHEAST QUADRANT 115 NM SOUTHWEST QUADRANT 115 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 080 DEG/ 02 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 180000Z --- 17.4S 170.8W MAX SUSTAINED WINDS - 070 KT, GUSTS 085 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 - 050 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 030 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 155 NM NORTHEAST QUADRANT 155 NM SOUTHEAST QUADRANT 125 NM SOUTHWEST QUADRANT 125 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 090 DEG/ 01 KTS --- 72 HRS, VALID AT: 190000Z --- 17.4S 170.4W MAX SUSTAINED WINDS - 085 KT, GUSTS 105 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 025 NM NORTHEAST QUADRANT 025 NM SOUTHEAST QUADRANT 025 NM SOUTHWEST QUADRANT 025 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 055 NM NORTHEAST QUADRANT 055 NM SOUTHEAST QUADRANT 050 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 170 NM NORTHEAST QUADRANT 175 NM SOUTHEAST QUADRANT 170 NM SOUTHWEST QUADRANT 170 NM NORTHWEST QUADRANT VECTOR TO 96 HR POSIT: 120 DEG/ 01 KTS --- LONG RANGE OUTLOOK: --- 96 HRS, VALID AT: 200000Z --- 17.5S 170.2W MAX SUSTAINED WINDS - 090 KT, GUSTS 110 KT WIND RADII VALID OVER OPEN WATER ONLY VECTOR TO 120 HR POSIT: 160 DEG/ 01 KTS --- 120 HRS, VALID AT: 210000Z --- 17.8S 170.1W MAX SUSTAINED WINDS - 085 KT, GUSTS 105 KT WIND RADII VALID OVER OPEN WATER ONLY --- REMARKS: 160300Z POSITION NEAR 18.9S 175.0W. TROPICAL CYCLONE 11P (WINSTON), LOCATED APPROXIMATELY 353 NM EAST-SOUTHEAST OF SUVA, FIJI, HAS TRACKED EAST-NORTHEASTWARD AT 13 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY INDICATES THAT DIURNAL BURST OF DEEP CONVECTION HAS WEAKENED OVER THE PAST SIX HOURS WITH SHALLOW CONVECTION NOW BANDING INTO A WEAK, CLOUD-COVERED LOW-LEVEL CIRCULATION CENTER (LLCC). A 152108Z 89 GHZ AMSU-B MICROWAVE IMAGE DEPICTS TIGHTLY CURVED BANDING WRAPPING INTO A BROAD, RAGGED MICROWAVE EYE FEATURE SUPPORTING THE INITIAL POSITION WITH GOOD CONFIDENCE. THE INITIAL INTENSITY IS ASSESSED AT 45 KNOTS BASED UPON MULTI-AGENCY DVORAK ESTIMATES BETWEEN T3.0 AND T3.5. TC WINSTON REMAINS IN A MARGINAL ENVIRONMENT, WITH HIGH SEA SURFACE TEMPERATURES (SSTS) ABOVE 31 DEGREES CELSIUS, BEING LIMITED BY A SINGLE OUTFLOW CHANNEL AROUND THE BASE OF AN UPPER-LEVEL TROUGH TO THE SOUTHEAST AND MODERATE (20 TO 25 KNOTS) VERTICAL WIND SHEAR (VWS). THIS WARNING CONTAINS A SIGNIFICANT CHANGE IN THE FORECAST PHILOSOPHY. TC WINSTON IS FORECAST TO CONTINUE TRACKING EAST-NORTHEASTWARD UNDER THE COMBINED INFLUENCE OF DEEP-LAYER SUBTROPICAL RIDGES (STR) TO THE WEST AND NORTH THROUGH TAU 36. AFTER TAU 36, THE WESTERN STR WILL BUILD AND BEGIN TO MOVE WESTWARD WHILE THE EASTERN STR WILL BUILD WHILE REMAINING NEARLY QUASI-STATIONARY, CAUSING TC WINSTON TO SLOW ITS FORWARD SPEED SIGNIFICANTLY, BECOMING QUASI-STATIONARY BY TAU 72. AFTER TAU 72, AND CONTRARY TO THE PREVIOUS FORECAST, THE SYSTEM WILL BEGIN A SLOW TURN TO THE SOUTHEAST TOWARDS AN INDUCED WEAKNESS IN THE RIDGE PATTERN AS THE RIDGE TO THE WEST WEAKENS AND MOVES FURTHER WESTWARD AND THE RIDGE TO THE EAST REORIENTS TO THE NORTH. TC WINSTON IS FORECAST TO GRADUALLY RE-INTENSIFY DURING THE FORECAST PERIOD AS IT TRACKS OVER WARMER (29-30C) SSTS AND THROUGH A REGION OF DECREASING VWS. A SLIGHT WEAKENING IS FORECAST BY TAU 120 AS THE SYSTEM BECOMES QUASI-STATIONARY AND INCREASED UPWELLING OF COOLER WATER OCCURS. DYNAMIC MODEL GUIDANCE IS IN POOR AGREEMENT AFTER TAU 36, WITH A BIFURCATION INTO TWO DISTINCT SOLUTIONS DUE TO HIGH UNCERTAINTY WITH THE OVERALL SYNOPTIC STEERING PATTERN, LEADING TO LOW CONFIDENCE IN THE JTWC FORECAST TRACK. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 160000Z IS 22 FEET. NEXT WARNINGS AT 161500Z AND 170300Z.//