WTPS31 PGTW 161500 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 05P (YASA) WARNING NR 017// RMKS/ 1. TROPICAL CYCLONE 05P (YASA) WARNING NR 017 02 ACTIVE TROPICAL CYCLONES IN SOUTHPAC MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 161200Z --- NEAR 15.2S 175.6E MOVEMENT PAST SIX HOURS - 110 DEGREES AT 06 KTS POSITION ACCURATE TO WITHIN 030 NM POSITION BASED ON EYE FIXED BY SATELLITE PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 140 KT, GUSTS 170 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 045 NM NORTHEAST QUADRANT 035 NM SOUTHEAST QUADRANT 035 NM SOUTHWEST QUADRANT 045 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 075 NM NORTHEAST QUADRANT 065 NM SOUTHEAST QUADRANT 065 NM SOUTHWEST QUADRANT 085 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 140 NM NORTHEAST QUADRANT 120 NM SOUTHEAST QUADRANT 120 NM SOUTHWEST QUADRANT 125 NM NORTHWEST QUADRANT REPEAT POSIT: 15.2S 175.6E --- FORECASTS: 12 HRS, VALID AT: 170000Z --- 16.1S 177.3E MAX SUSTAINED WINDS - 140 KT, GUSTS 170 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: 130 DEG/ 10 KTS --- 24 HRS, VALID AT: 171200Z --- 17.4S 179.0E MAX SUSTAINED WINDS - 125 KT, GUSTS 150 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: 140 DEG/ 10 KTS --- 36 HRS, VALID AT: 180000Z --- 18.9S 179.6W MAX SUSTAINED WINDS - 110 KT, GUSTS 135 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: 155 DEG/ 07 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 181200Z --- 20.1S 179.0W 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 - 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: 180 DEG/ 06 KTS --- 72 HRS, VALID AT: 191200Z --- 22.4S 179.1W MAX SUSTAINED WINDS - 080 KT, GUSTS 100 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 020 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: 201200Z --- 24.5S 179.4E MAX SUSTAINED WINDS - 055 KT, GUSTS 070 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: 225 DEG/ 05 KTS --- 120 HRS, VALID AT: 211200Z --- 26.0S 177.8E 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: 161500Z POSITION NEAR 15.4S 176.0E. 16DEC20. TROPICAL CYCLONE (TC) 05P (YASA), LOCATED APPROXIMATELY 237 NM NORTHWEST OF SUVA, FIJI, HAS TRACKED EAST-SOUTHEASTWARD AT 06 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS SPIRAL BANDS OF DEEP CONVECTION WRAPPING INTO A 20 NM EYE WITH TRANSVERSE BANDING ALONG THE WESTERN PORTION OF THE SYSTEM. THE INITIAL POSITION IS PLACED WITH HIGH CONFIDENCE BASED ON THE POSITION OF THE EYE IN THE EIR LOOP. THE INITIAL INTENSITY OF 140 KTS IS ASSESSED WITH HIGH CONFIDENCE BASED ON MULTI-AGENCY DVORAK CURRENT INTENSITY ESTIMATES OF T7.0 (140 KTS, PGTW AND KNES) AND A CIMSS ADVANCED DVORAK TECHNIQUE CURRENT INTENSITY ESTIMATE OF T6.8 (135 KTS). TC YASA IS TRACKING ALONG THE NORTHWESTERN PERIPHERY OF A SUBTROPICAL RIDGE (STR) POSITIONED TO THE SOUTHEAST AND THROUGH A FAVORABLE ENVIRONMENT WITH WARM (28-29 CELSIUS) SEA SURFACE TEMPERATURES (SST), LOW (10-15 KTS) VWS, AND ROBUST POLEWARD AND EQUATORWARD OUTFLOW ALOFT. CONTINUED FAVORABLE ENVIRONMENTAL CONDITIONS WILL ALLOW TC YASA TO MAINTAIN AN INTENSITY OF 140 KTS THROUGH TAU 12. THEREAFTER, VWS WILL INCREASE AND LEAD TO A GRADUAL WEAKENING OF THE SYSTEM. TC YASA WILL TRACK ALONG THE WEST COAST OF VANUA LEVU, FIJI BETWEEN TAU 12 AND TAU 24 AND WEAKEN TO 125 KTS BY THAT TIME. THEREAFTER, MODERATE (15-20 KTS) VWS WILL LEAD TO FURTHER WEAKENING TO 100 KTS BY TAU 48. AT THIS TIME, TC YASA WILL BEGIN TO TRACK ALONG THE NORTHERN PERIPHERY OF AN STR POSITIONED TO THE SOUTH AS THE CURRENT STEERING RIDGE WEAKENS DUE TO INTERACTION WITH AN INCOMING MIDLATITUDE TROUGH FROM THE WEST. THIS CHANGE IN STEERING WILL RESULT IN A GENERALLY SOUTHWESTWARD TRACK THROUGH THE REMAINDER OF THE FORECAST PERIOD. INCREASING VWS WILL LEAD TO FURTHER WEAKENING TO 80 KTS BY TAU 72 AND HIGH (30+ KTS) VWS THEREAFTER, COUPLED WITH COOL (< 26 CELSIUS) SST, WILL FURTHER WEAKEN THE SYSTEM TO 40 KTS BY TAU 120. NUMERICAL MODEL TRACK GUIDANCE IS IN POOR AGREEMENT WITH A 75 NM SPREAD IN ACROSS TRACK MODEL SOLUTIONS AT TAU 24 THAT INCREASES TO 630 NM BY TAU 120. THE MODEL TRACK ENVELOPE IS BOUND BY THE GFS SOLUTIONS TO THE WEST AND THE ECMWF SOLUTIONS TO THE EAST WITH THE UKMET, GALWEM AND NAVGEM SOLUTIONS CLOSER TO THE MULTI-MODEL CONSENSUS. THE JTWC FORECAST TRACK IS PLACED NEAR THE MULTI-MODEL CONSENSUS. WHILE THE JTWC FORECAST TRACK BRINGS THE SYSTEM CENTER BETWEEN THE ISLANDS OF VITI LEVU AND VANUA LEVU, THE SPREAD IN MODEL SOLUTIONS YIELDS THE POSSIBILITY OF LANDFALL ON EITHER ISLAND WITH THE GFS AND NAVGEM SOLUTIONS TRACKING OVER VITI LEVU AND ECMWF, UKMET AND GALWEM MODELS PROVIDING TRACKS THAT BRING THE VORTEX OVER VANUA LEVU. THIS SPREAD IN MODEL SOLUTIONS LENDS HIGH CONFIDENCE IN THE INITIAL PORTION OF THE JTWC FORECAST TRACK THROUGH TAU 24 AND LOW CONFIDENCE THEREAFTER AS THE MODEL SOLUTIONS FURTHER DIVERGE. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 161200Z IS 38 FEET. NEXT WARNINGS AT 162100Z, 170300Z, 170900Z AND 171500Z. REFER TO TROPICAL CYCLONE 06P (ZAZU) WARNINGS (WTPS32 PGTW) FOR THE FINAL WARNING.// NNNN