WTPS31 PGTW 162100 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 05P (YASA) WARNING NR 018// RMKS/ 1. TROPICAL CYCLONE 05P (YASA) WARNING NR 018 01 ACTIVE TROPICAL CYCLONE IN SOUTHPAC MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 161800Z --- NEAR 15.5S 176.7E MOVEMENT PAST SIX HOURS - 105 DEGREES AT 11 KTS POSITION ACCURATE TO WITHIN 015 NM POSITION BASED ON CENTER LOCATED BY A COMBINATION OF SATELLITE AND RADAR PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 135 KT, GUSTS 165 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 055 NM NORTHEAST QUADRANT 050 NM SOUTHEAST QUADRANT 050 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 090 NM NORTHEAST QUADRANT 090 NM SOUTHEAST QUADRANT 075 NM SOUTHWEST QUADRANT 080 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 180 NM NORTHEAST QUADRANT 150 NM SOUTHEAST QUADRANT 140 NM SOUTHWEST QUADRANT 140 NM NORTHWEST QUADRANT REPEAT POSIT: 15.5S 176.7E --- FORECASTS: 12 HRS, VALID AT: 170600Z --- 16.5S 178.5E MAX SUSTAINED WINDS - 130 KT, GUSTS 160 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 050 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 090 NM NORTHEAST QUADRANT 080 NM SOUTHEAST QUADRANT 070 NM SOUTHWEST QUADRANT 060 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 170 NM NORTHEAST QUADRANT 150 NM SOUTHEAST QUADRANT 150 NM SOUTHWEST QUADRANT 140 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 135 DEG/ 10 KTS --- 24 HRS, VALID AT: 171800Z --- 17.9S 179.9W MAX SUSTAINED WINDS - 115 KT, GUSTS 140 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 040 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 090 NM NORTHEAST QUADRANT 080 NM SOUTHEAST QUADRANT 070 NM SOUTHWEST QUADRANT 060 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 180 NM NORTHEAST QUADRANT 170 NM SOUTHEAST QUADRANT 150 NM SOUTHWEST QUADRANT 130 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 145 DEG/ 08 KTS --- 36 HRS, VALID AT: 180600Z --- 19.3S 178.9W MAX SUSTAINED WINDS - 100 KT, GUSTS 125 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 040 NM NORTHEAST QUADRANT 030 NM SOUTHEAST QUADRANT 030 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 080 NM NORTHEAST QUADRANT 080 NM SOUTHEAST QUADRANT 070 NM SOUTHWEST QUADRANT 060 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 170 NM NORTHEAST QUADRANT 170 NM SOUTHEAST QUADRANT 150 NM SOUTHWEST QUADRANT 120 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 165 DEG/ 08 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 181800Z --- 20.9S 178.5W MAX SUSTAINED WINDS - 085 KT, GUSTS 105 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 040 NM NORTHEAST QUADRANT 030 NM SOUTHEAST QUADRANT 030 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 060 NM NORTHEAST QUADRANT 080 NM SOUTHEAST QUADRANT 070 NM SOUTHWEST QUADRANT 060 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 150 NM NORTHEAST QUADRANT 170 NM SOUTHEAST QUADRANT 150 NM SOUTHWEST QUADRANT 110 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 190 DEG/ 05 KTS --- 72 HRS, VALID AT: 191800Z --- 23.0S 178.9W MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 010 NM NORTHEAST QUADRANT 020 NM SOUTHEAST QUADRANT 030 NM SOUTHWEST QUADRANT 020 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 050 NM NORTHEAST QUADRANT 070 NM SOUTHEAST QUADRANT 060 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 130 NM NORTHEAST QUADRANT 150 NM SOUTHEAST QUADRANT 130 NM SOUTHWEST QUADRANT 100 NM NORTHWEST QUADRANT VECTOR TO 96 HR POSIT: 215 DEG/ 06 KTS --- LONG RANGE OUTLOOK: --- 96 HRS, VALID AT: 201800Z --- 24.9S 179.6E MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 010 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 110 NM NORTHEAST QUADRANT 150 NM SOUTHEAST QUADRANT 120 NM SOUTHWEST QUADRANT 080 NM NORTHWEST QUADRANT VECTOR TO 120 HR POSIT: 215 DEG/ 06 KTS --- 120 HRS, VALID AT: 211800Z --- 26.8S 178.0E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 090 NM NORTHEAST QUADRANT 150 NM SOUTHEAST QUADRANT 120 NM SOUTHWEST QUADRANT 080 NM NORTHWEST QUADRANT --- REMARKS: 162100Z POSITION NEAR 15.8S 177.2E. 16DEC20. TROPICAL CYCLONE (TC) 05P (YASA), LOCATED APPROXIMATELY 184 NM NORTH-NORTHWEST OF SUVA, FIJI, HAS TRACKED EAST-SOUTHEASTWARD AT 11 KNOTS (KTS) OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) REVEALS DEEP CONVECTIVE BANDS WRAPPING INTO A 22 NM EYE. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE DEFINED EYE IN MSI. ANIMATED WATER VAPOR IMAGERY INDICATES SOME PRESSURE AND CONVERGENCE ALONG THE WESTERN PERIPHERY OF THE SYSTEM. THE INITIAL INTENSITY OF 135 KTS IS ASSESSED WITH GOOD CONFIDENCE AND IS HEDGED BETWEEN DVORAK CURRENT INTENSITY ESTIMATES OF T6.5-7.0 (127-140 KTS, KNES AND PGTW). THIS IS FURTHER SUPPORTED BY A SATCON ESTIMATE OF 137 KTS. ENVIRONMENTAL ANALYSIS REVEALS AN OVERALL FAVORABLE ENVIRONMENT CHARACTERIZED BY WARM (28-29 CELSIUS) SEA SURFACE TEMPERATURES (SST), LOW (5-10 KTS) VERTICAL WIND SHEAR (VWS), GOOD EQUATORWARD OUTFLOW, AND ENHANCED POLEWARD OUTFLOW ALOFT. THE SYSTEM IS TRACKING GENERALLY SOUTHEASTWARD ALONG THE NORTHWESTERN PERIPHERY OF A SUBTROPICAL RIDGE (STR) POSITIONED TO THE SOUTHEAST. IN THE NEAR TERM, THE SYSTEM IS EXPECTED TO TRACK GENERALLY SOUTHEASTWARD WITH THE MODEL SOLUTIONS IN FAIR AGREEMENT. AS TC 05P HAS TRACKED FURTHER EASTWARD, THE JTWC FORECAST TRACK HAS ALSO MOVED EASTWARD AND IS NOW EXPECTED TO TRACK OVER VANUA LEVU, FIJI SHORTLY AFTER TAU 12. THROUGHOUT THIS TRANSIT, THE SYSTEM SHOULD GRADUALLY WEAKEN DUE TO MODERATE VWS AND LAND INTERACTION, DECREASING INTENSITY TO 115 KTS BY TAU 24. AN INCOMING MIDLATITUDE SHORTWAVE TROUGH FROM THE WEST WILL WEAKEN THE CURRENT STEERING RIDGE AROUND TAU 36, CAUSING A STR POSITIONED TO THE SOUTH TO TAKE OVER AS THE PRIMARY STEERING MECHANISM. AT THIS TIME, THE SYSTEM WILL BEGIN TO TURN SOUTHWESTWARD ALONG THE NORTHERN PERIPHERY OF THE STEERING STR AND THE SYSTEM SHOULD MAINTAIN THIS GENERAL TRACK FOR THE REMAINDER OF THE FORECAST PERIOD. COOL (<26 CELSIUS) SST AND HIGH (>25 KTS) VWS WILL CONTINUE TO WEAKEN THE SYSTEM IN THE EXTENDED FORECAST, LEADING TC 05P TO WEAKEN TO 40 KTS BY TAU 120. SIMILAR TO PREVIOUS MODEL RUNS, THE MODEL TRACK ENVELOPE IS BOUND BY THE GFS SOLUTIONS TO THE WEST AND THE ECMWF SOLUTIONS TO THE EAST. OF NOTE, THE UKMET AND GALWEM SOLUTIONS HAVE MOVED INTO BETTER AGREEMENT WITH THE ECMWF SOLUTIONS, LENDING SUPPORT TO THE EASTWARD SHIFT OF THE JTWC FORECAST TRACK. THE JTWC FORECAST TRACK REMAINS NEAR THE MULTI-MODEL CONSENSUS. HOWEVER, DUE TO INCREASING MODEL SPREAD AFTER TAU 12, THERE IS LOW CONFIDENCE IN THE JTWC FORECAST TRACK. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 161800Z IS 36 FEET. NEXT WARNINGS AT 170300Z, 170900Z, 171500Z AND 172100Z.// NNNN