WTPS31 PGTW 200300 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 05P (YASA) WARNING NR 031// RMKS/ 1. TROPICAL CYCLONE 05P (YASA) WARNING NR 031 01 ACTIVE TROPICAL CYCLONE IN SOUTHPAC MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 200000Z --- NEAR 23.3S 178.1W MOVEMENT PAST SIX HOURS - 210 DEGREES AT 06 KTS POSITION ACCURATE TO WITHIN 020 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 BECOMING SUBTROPICAL RADIUS OF 050 KT WINDS - 000 NM NORTHEAST QUADRANT 065 NM SOUTHEAST QUADRANT 060 NM SOUTHWEST QUADRANT 045 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 125 NM NORTHEAST QUADRANT 165 NM SOUTHEAST QUADRANT 135 NM SOUTHWEST QUADRANT 095 NM NORTHWEST QUADRANT REPEAT POSIT: 23.3S 178.1W --- FORECASTS: 12 HRS, VALID AT: 201200Z --- 24.1S 178.7W MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY SUBTROPICAL RADIUS OF 034 KT WINDS - 105 NM NORTHEAST QUADRANT 160 NM SOUTHEAST QUADRANT 110 NM SOUTHWEST QUADRANT 070 NM NORTHWEST QUADRANT --- REMARKS: 200300Z POSITION NEAR 23.5S 178.2W. 20DEC20. TROPICAL CYCLONE 05P (YASA), LOCATED APPROXIMATELY 369 NM SOUTH-SOUTHEAST OF SUVA, FIJI, HAS TRACKED SOUTH-SOUTHWESTWARD AT 06 KNOTS OVER THE PAST SIX HOURS. THE CURRENT POSITION IS SITUATED WITHIN AN EXPOSED LOW-LEVEL CIRCULATION EVIDENT IN RECENT VISIBLE SATELLITE IMAGERY. THE INTENSITY OF 50 KNOTS IS SUPPORTED BY A 191930Z SCATSAT PASS AND RECENT AUTOMATED INTENSITY ESTIMATES FROM CIMSS AND CIRA. TC 05P IS TRACKING SOUTH-SOUTHWESTWARD UNDER THE STEERING INFLUENCE SUBTROPICAL RIDGING TO THE SOUTH AND EAST. THE SYSTEM IS RAPIDLY TRANSITIONED INTO A SUBTROPICAL CYCLONE AS IT PASSES OVER COOLER WATER AND INTERACTS WITH UPPER-LEVEL TROUGHING. FAVORABLE BAROCLINIC INTERACTION BETWEEN THE SURFACE LOW AND UPPER- TROUGHING HAVE ENABLED TC 05P TO MAINTAIN INTENSITY OVER THE PAST SIX HOURS DESPITE STRONG VERTICAL WIND SHEAR (OVER 30 KNOTS) AND PASSAGE OVER COOLER WATER (25-26C). FULL TRANSITION INTO A SUBTROPICAL CYCLONE IS IMMINENT. THE SYSTEM WILL CONTINUE TO FOLLOW THE SUBTROPICAL STEERING FLOW SOUTHWESTWARD FOR THE NEXT 12 HOURS, AND WILL LIKELY MAINTAIN INTENSITY OR WEAKEN ONLY SLIGHTLY WITH PERSISTENCE OF THE ENVIRONMENTAL FACTORS DISCUSSED ABOVE. NUMERICAL MODELS ARE IN EXCELLENT AGREEMENT THROUGH TAU 12, LENDING HIGH CONFIDENCE TO THE TRACK FORECAST. THIS IS THE FINAL WARNING ON THIS SYSTEM BY THE JOINT TYPHOON WRNCEN PEARL HARBOR HI. THE SYSTEM WILL BE CLOSELY MONITORED FOR SIGNS OF REGENERATION. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 200000Z IS 20 FEET.// NNNN