WTPS31 PGTW 010300 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 23P (TWENTYTHREE) WARNING NR 001// REF/A/MSG/JOINT TYPHOON WRNCEN PEARL HARBOR HI/281251ZFEB2021// AMPN/REF A IS A TROPICAL CYCLONE FORMATION ALERT.// RMKS/ 1. TROPICAL CYCLONE 23P (TWENTYTHREE) WARNING NR 001 01 ACTIVE TROPICAL CYCLONE IN SOUTHPAC MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 010000Z --- NEAR 17.2S 147.2E MOVEMENT PAST SIX HOURS - 280 DEGREES AT 05 KTS POSITION ACCURATE TO WITHIN 045 NM POSITION BASED ON CENTER LOCATED BY A COMBINATION OF SATELLITE, RADAR AND SYNOPTIC DATA PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 060 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 100 NM SOUTHWEST QUADRANT 080 NM NORTHWEST QUADRANT REPEAT POSIT: 17.2S 147.2E --- FORECASTS: 12 HRS, VALID AT: 011200Z --- 16.5S 147.3E MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 050 NM NORTHEAST QUADRANT 110 NM SOUTHEAST QUADRANT 100 NM SOUTHWEST QUADRANT 090 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 045 DEG/ 03 KTS --- 24 HRS, VALID AT: 020000Z --- 16.0S 147.8E MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 070 NM NORTHEAST QUADRANT 130 NM SOUTHEAST QUADRANT 120 NM SOUTHWEST QUADRANT 090 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 080 DEG/ 03 KTS --- 36 HRS, VALID AT: 021200Z --- 15.9S 148.4E MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 100 NM NORTHEAST QUADRANT 100 NM SOUTHEAST QUADRANT 120 NM SOUTHWEST QUADRANT 080 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 135 DEG/ 01 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 030000Z --- 16.1S 148.6E MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 040 NM NORTHEAST QUADRANT 020 NM SOUTHEAST QUADRANT 030 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 120 NM NORTHEAST QUADRANT 110 NM SOUTHEAST QUADRANT 130 NM SOUTHWEST QUADRANT 110 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 155 DEG/ 01 KTS --- 72 HRS, VALID AT: 040000Z --- 16.3S 148.7E MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 030 NM NORTHEAST QUADRANT 020 NM SOUTHEAST QUADRANT 020 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 180 NM NORTHEAST QUADRANT 110 NM SOUTHEAST QUADRANT 100 NM SOUTHWEST QUADRANT 160 NM NORTHWEST QUADRANT VECTOR TO 96 HR POSIT: 115 DEG/ 06 KTS --- LONG RANGE OUTLOOK: --- 96 HRS, VALID AT: 050000Z --- 17.3S 151.1E MAX SUSTAINED WINDS - 060 KT, GUSTS 075 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 050 NM NORTHEAST QUADRANT 020 NM SOUTHEAST QUADRANT 030 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 180 NM NORTHEAST QUADRANT 090 NM SOUTHEAST QUADRANT 110 NM SOUTHWEST QUADRANT 190 NM NORTHWEST QUADRANT VECTOR TO 120 HR POSIT: 120 DEG/ 14 KTS --- 120 HRS, VALID AT: 060000Z --- 20.1S 156.3E MAX SUSTAINED WINDS - 070 KT, GUSTS 085 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 040 NM NORTHEAST QUADRANT 020 NM SOUTHEAST QUADRANT 030 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 060 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 060 NM SOUTHWEST QUADRANT 070 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 220 NM NORTHEAST QUADRANT 120 NM SOUTHEAST QUADRANT 140 NM SOUTHWEST QUADRANT 190 NM NORTHWEST QUADRANT --- REMARKS: 010300Z POSITION NEAR 17.0S 147.2E. 01MAR21. TROPICAL CYCLONE (TC) 23P (TWENTYTHREE), LOCATED APPROXIMATELY 82 NM EAST-SOUTHEAST OF CAIRNS, AUSTRALIA, HAS TRACKED WESTWARD AT 05 KNOTS OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS A PARTIALLY-EXPOSED, WELL- DEFINED LOW-LEVEL CIRCULATION CENTER (LLCC) POSITIONED ALONG THE EASTERN EDGE OF A LARGE CLUSTER OF PERSISTENT DEEP CONVECTION. DESPITE MODERATE TO STRONG (20-25 KNOT) NORTHEASTERLY VERTICAL WIND SHEAR (VWS), THERE IS GOOD EVIDENCE THAT THE SYSTEM HAS CONSOLIDATED OVER THE PAST TWELVE HOURS: FIRST, A 282030Z MHS 89GHZ MICROWAVE IMAGE REVEALS MULTIPLE SHALLOW BANDS WRAPPING TIGHTLY INTO A DEFINED LLCC; SECOND, SURFACE OBSERVATIONS FROM LUCINDA AND HOLMES REEF INDICATE PEAK SUSTAINED WINDS OF 35-40 KNOTS (1-MINUTE AVERAGE); THIRD, FLINDER'S REEF REPORTED MINIMUM SLP OF 996MB, WHICH CORRESPONDS TO A 35 KNOT SYSTEM, WITH A SIGNIFICANT 4-5MB 24-HOUR SLP DECREASE. DVORAK ESTIMATES ALSO SUPPORT THE 35-KNOT INTENSITY ASSESSMENT AND RANGE FROM T2.0 (30 KNOTS) TO T2.5 (35 KNOTS). ENVIRONMENTAL ANALYSIS DEPICTS A MARGINAL ENVIRONMENT WITH THE MODERATE TO STRONG VWS OFFSET BY ROBUST POLEWARD OUTFLOW AND WARM SST VALUES (30C). THE CURRENT STEERING ENVIRONMENT IS VERY COMPLEX WITH A STRONG SUBTROPICAL RIDGE (STR) OVER EASTERN AUSTRALIA AND ANOTHER STR EAST AND SOUTH OF THE SYSTEM. ADDITIONALLY, A STRONG NEAR-EQUATORIAL RIDGE IS ENTRENCHED NORTH OF THE SYSTEM. CONSEQUENTLY, TC 23P IS BOXED IN AND THE TRACK MOTION IS EXPECTED TO BE SLOW, LIMITED AND ERRATIC THROUGH TAU 72 DUE TO A COMBINATION OF THESE STEERING INFLUENCES. THE JTWC FORECAST TRACK INDICATES A CLOCKWISE LOOP WHICH IS IN LINE WITH THE BULK OF THE NUMERICAL MODEL GUIDANCE THROUGH TAU 72. THERE IS OBVIOUSLY HIGH UNCERTAINTY (LOW CONFIDENCE) IN THE TRACK DUE TO THE AFOREMENTIONED COMPLEX STEERING ENVIRONMENT. VWS WILL DECREASE THUS THE SYSTEM IS FORECAST TO GRADUALLY INTENSIFY THROUGH TAU 72. AFTER TAU 72, A MAJOR MIDLATITUDE TROUGH IS FORECAST TO DEEPEN TO THE SOUTH, WHICH WILL ERODE THE STR AND ALLOW THE SYSTEM TO ACCELERATE EAST-SOUTHEASTWARD ALONG THE SOUTHERN PERIPHERY OF THE NEAR-EQUATORIAL RIDGE THROUGH THE REMAINDER OF THE PERIOD. THIS TROUGH WILL ALSO IMPROVE POLEWARD VENTING WHICH WILL LEAD TO A SHARPER INTENSIFICATION RATE WITH A PEAK INTENSITY OF 70 KNOTS ANTICIPATED BY TAU 120. OVERALL, THERE IS LOW CONFIDENCE IN THE JTWC FORECAST TRACK. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 010000Z IS 14 FEET. NEXT WARNINGS AT 010900Z, 011500Z, 012100Z AND 020300Z. 2. THIS CANCELS AND SUPERSEDES REF A (WTPS21 PGTW 281300).// NNNN