WTPS31 PGTW 301500 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 15P (ANA) WARNING NR 003// RMKS/ 1. TROPICAL CYCLONE 15P (ANA) WARNING NR 003 01 ACTIVE TROPICAL CYCLONE IN SOUTHPAC MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 301200Z --- NEAR 16.8S 177.4E MOVEMENT PAST SIX HOURS - 130 DEGREES AT 05 KTS POSITION ACCURATE TO WITHIN 045 NM POSITION BASED ON CENTER LOCATED BY A COMBINATION OF SATELLITE AND SYNOPTIC DATA PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 070 NM NORTHEAST QUADRANT 075 NM SOUTHEAST QUADRANT 055 NM SOUTHWEST QUADRANT 055 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 165 NM NORTHEAST QUADRANT 130 NM SOUTHEAST QUADRANT 075 NM SOUTHWEST QUADRANT 210 NM NORTHWEST QUADRANT REPEAT POSIT: 16.8S 177.4E --- FORECASTS: 12 HRS, VALID AT: 310000Z --- 17.7S 177.9E MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 050 NM NORTHEAST QUADRANT 070 NM SOUTHEAST QUADRANT 000 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 190 NM NORTHEAST QUADRANT 120 NM SOUTHEAST QUADRANT 040 NM SOUTHWEST QUADRANT 130 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 170 DEG/ 07 KTS --- 24 HRS, VALID AT: 311200Z --- 19.0S 178.2E MAX SUSTAINED WINDS - 055 KT, GUSTS 070 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 050 NM NORTHEAST QUADRANT 060 NM SOUTHEAST QUADRANT 020 NM SOUTHWEST QUADRANT 000 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 240 NM NORTHEAST QUADRANT 140 NM SOUTHEAST QUADRANT 090 NM SOUTHWEST QUADRANT 080 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 170 DEG/ 08 KTS --- 36 HRS, VALID AT: 010000Z --- 20.5S 178.5E MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 090 NM NORTHEAST QUADRANT 070 NM SOUTHEAST QUADRANT 050 NM SOUTHWEST QUADRANT 000 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 260 NM NORTHEAST QUADRANT 160 NM SOUTHEAST QUADRANT 130 NM SOUTHWEST QUADRANT 070 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 165 DEG/ 08 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 011200Z --- 22.0S 179.0E MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 090 NM NORTHEAST QUADRANT 070 NM SOUTHEAST QUADRANT 050 NM SOUTHWEST QUADRANT 000 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 240 NM NORTHEAST QUADRANT 180 NM SOUTHEAST QUADRANT 140 NM SOUTHWEST QUADRANT 090 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 145 DEG/ 08 KTS --- 72 HRS, VALID AT: 021200Z --- 24.7S 179.0W MAX SUSTAINED WINDS - 045 KT, GUSTS 055 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 034 KT WINDS - 180 NM NORTHEAST QUADRANT 140 NM SOUTHEAST QUADRANT 110 NM SOUTHWEST QUADRANT 070 NM NORTHWEST QUADRANT VECTOR TO 96 HR POSIT: 140 DEG/ 10 KTS --- LONG RANGE OUTLOOK: --- 96 HRS, VALID AT: 031200Z --- 27.6S 176.1W MAX SUSTAINED WINDS - 035 KT, GUSTS 045 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER RADIUS OF 034 KT WINDS - 080 NM NORTHEAST QUADRANT 100 NM SOUTHEAST QUADRANT 090 NM SOUTHWEST QUADRANT 020 NM NORTHWEST QUADRANT VECTOR TO 120 HR POSIT: 130 DEG/ 10 KTS --- 120 HRS, VALID AT: 041200Z --- 30.2S 172.6W MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER --- REMARKS: 301500Z POSITION NEAR 17.0S 177.5E. 30JAN21. TROPICAL CYCLONE (TC) 15P (ANA), LOCATED APPROXIMATELY 97 NM NORTHWEST OF SUVA, FIJI, HAS TRACKED SOUTHEASTWARD AT 05 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY DEPICTS A CONSOLIDATING SYSTEM WITH SPIRAL BANDING WRAPPING INTO A DEFINED LOW-LEVEL CIRCULATION CENTER. A PARTIAL 300830Z ASCAT- A IMAGE AND 30/12Z SURFACE OBSERVATIONS FROM VIWA ISLAND (91670) AND RAKIRAKI (91669) SUPPORT THE INITIAL POSITION AND INDICATE 35-40 KNOT WINDS OVER THE WESTERN AND SOUTHERN SEMICIRCLES. ADDITIONALLY, RAKIRAKI IS REPORTING A SLP OF 989.3MB, WHICH CORRESPONDS TO ABOUT 45 KNOTS. THE INITIAL INTENSITY OF 50 KNOTS IS ASSESSED SLIGHTLY HIGHER BASED ON DVORAK INTENSITY ESTIMATES RANGING FROM T3.0-3.5 (45- 55 KNOTS). A 300943Z MHS 89GHZ MICROWAVE IMAGE REVEALS A PARTIALLY- EXPOSED LOW-LEVEL CIRCULATION WITH A SMALL CONVECTIVE BAND OVER THE NORTHERN SEMICIRCLE AND A MORE EXTENSIVE PRIMARY BAND OVER THE EASTERN PERIPHERY. OVERALL, THERE IS GOOD CONFIDENCE IN THE INITIAL POSITION. UPPER-LEVEL ANALYSIS INDICATES A FAVORABLE ENVIRONMENT WITH LOW VERTICAL WIND SHEAR (VWS) AND ROBUST EQUATORWARD OUTFLOW. ADDITIONALLY, SST VALUES (29-30C) REMAIN CONDUCIVE. HOWEVER, POLEWARD OUTFLOW IS WEAK DUE TO CONVERGENT FLOW OVER THE SOUTHWEST QUADRANT AND THE LACK OF A SIGNIFICANT UPPER-LEVEL TROUGH, WHICH HAS PROPAGATED EASTWARD. TC 15P IS FORECAST TO REACH A PEAK INTENSITY OF 55 KNOTS WITHIN THE NEXT 24 HOURS AS IT TURNS SOUTHWARD ALONG THE WESTERN PERIPHERY OF A SUBTROPICAL RIDGE (STR) EXTENSION TO THE EAST, HOWEVER, INTERACTION WITH LAND SHOULD LIMIT DEVELOPMENT. AFTER TAU 24, TC 15P IS EXPECTED TO ACCELERATE SOUTH-SOUTHEASTWARD TO SOUTHEASTWARD ALONG THE SOUTHWESTERN PERIPHERY OF THE STR WITH INCREASING VWS (20-25 KNOTS) HINDERING DEVELOPMENT. AFTER TAU 48, TC 15P SHOULD CONTINUE TO WEAKEN AS IT ENCOUNTERS STRONG VWS (30-35 KNOTS) ASSOCIATED WITH THE SUBTROPICAL WESTERLIES AS WELL AS SLIGHTLY COOLER SST (26-27C). IN THE EXTENDED PERIOD, THE SYSTEM WILL WEAKEN MORE RAPIDLY DUE TO COOL SST (26-23C) AND SHOULD DISSIPATE BY TAU 120. NUMERICAL MODEL GUIDANCE REMAINS IN GOOD AGREEMENT THROUGH TAU 72 LENDING HIGH CONFIDENCE TO THE JTWC FORECAST TRACK WITH A 150NM SPREAD IN MODEL SOLUTIONS AT TAU 72. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 301200Z IS 16 FEET. NEXT WARNINGS AT 302100Z, 310300Z, 310900Z AND 311500Z.// NNNN