WTPS31 PGTW 302100 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/TROPICAL CYCLONE 15P (ANA) WARNING NR 004// RMKS/ 1. TROPICAL CYCLONE 15P (ANA) WARNING NR 004 02 ACTIVE TROPICAL CYCLONES IN SOUTHPAC MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE WIND RADII VALID OVER OPEN WATER ONLY --- WARNING POSITION: 301800Z --- NEAR 17.5S 178.2E MOVEMENT PAST SIX HOURS - 130 DEGREES AT 09 KTS POSITION ACCURATE TO WITHIN 030 NM POSITION BASED ON CENTER LOCATED BY A COMBINATION OF SATELLITE, RADAR AND SYNOPTIC DATA PRESENT WIND DISTRIBUTION: MAX SUSTAINED WINDS - 060 KT, GUSTS 075 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 070 NM NORTHEAST QUADRANT 075 NM SOUTHEAST QUADRANT 050 NM SOUTHWEST QUADRANT 050 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 185 NM NORTHEAST QUADRANT 140 NM SOUTHEAST QUADRANT 095 NM SOUTHWEST QUADRANT 205 NM NORTHWEST QUADRANT REPEAT POSIT: 17.5S 178.2E --- FORECASTS: 12 HRS, VALID AT: 310600Z --- 18.5S 178.7E MAX SUSTAINED WINDS - 060 KT, GUSTS 075 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 050 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 020 NM SOUTHWEST QUADRANT 010 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 200 NM NORTHEAST QUADRANT 140 NM SOUTHEAST QUADRANT 090 NM SOUTHWEST QUADRANT 150 NM NORTHWEST QUADRANT VECTOR TO 24 HR POSIT: 175 DEG/ 06 KTS --- 24 HRS, VALID AT: 311800Z --- 19.7S 178.8E MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 030 NM NORTHEAST QUADRANT 040 NM SOUTHEAST QUADRANT 000 NM SOUTHWEST QUADRANT 000 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 060 NM NORTHEAST QUADRANT 060 NM SOUTHEAST QUADRANT 030 NM SOUTHWEST QUADRANT 020 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 220 NM NORTHEAST QUADRANT 160 NM SOUTHEAST QUADRANT 140 NM SOUTHWEST QUADRANT 130 NM NORTHWEST QUADRANT VECTOR TO 36 HR POSIT: 165 DEG/ 08 KTS --- 36 HRS, VALID AT: 010600Z --- 21.2S 179.2E MAX SUSTAINED WINDS - 065 KT, GUSTS 080 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 064 KT WINDS - 020 NM NORTHEAST QUADRANT 030 NM SOUTHEAST QUADRANT 000 NM SOUTHWEST QUADRANT 000 NM NORTHWEST QUADRANT RADIUS OF 050 KT WINDS - 070 NM NORTHEAST QUADRANT 060 NM SOUTHEAST QUADRANT 050 NM SOUTHWEST QUADRANT 030 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 240 NM NORTHEAST QUADRANT 180 NM SOUTHEAST QUADRANT 160 NM SOUTHWEST QUADRANT 110 NM NORTHWEST QUADRANT VECTOR TO 48 HR POSIT: 145 DEG/ 08 KTS --- EXTENDED OUTLOOK: 48 HRS, VALID AT: 011800Z --- 22.5S 179.9W MAX SUSTAINED WINDS - 060 KT, GUSTS 075 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 080 NM NORTHEAST QUADRANT 060 NM SOUTHEAST QUADRANT 050 NM SOUTHWEST QUADRANT 020 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 220 NM NORTHEAST QUADRANT 170 NM SOUTHEAST QUADRANT 140 NM SOUTHWEST QUADRANT 110 NM NORTHWEST QUADRANT VECTOR TO 72 HR POSIT: 145 DEG/ 09 KTS --- 72 HRS, VALID AT: 021800Z --- 25.5S 177.5W MAX SUSTAINED WINDS - 050 KT, GUSTS 065 KT WIND RADII VALID OVER OPEN WATER ONLY RADIUS OF 050 KT WINDS - 080 NM NORTHEAST QUADRANT 060 NM SOUTHEAST QUADRANT 030 NM SOUTHWEST QUADRANT 040 NM NORTHWEST QUADRANT RADIUS OF 034 KT WINDS - 150 NM NORTHEAST QUADRANT 140 NM SOUTHEAST QUADRANT 120 NM SOUTHWEST QUADRANT 090 NM NORTHWEST QUADRANT VECTOR TO 96 HR POSIT: 145 DEG/ 11 KTS --- LONG RANGE OUTLOOK: --- 96 HRS, VALID AT: 031800Z --- 29.1S 174.5W MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER RADIUS OF 034 KT WINDS - 090 NM NORTHEAST QUADRANT 110 NM SOUTHEAST QUADRANT 100 NM SOUTHWEST QUADRANT 080 NM NORTHWEST QUADRANT VECTOR TO 120 HR POSIT: 130 DEG/ 11 KTS --- 120 HRS, VALID AT: 041800Z --- 32.0S 170.5W MAX SUSTAINED WINDS - 030 KT, GUSTS 040 KT WIND RADII VALID OVER OPEN WATER ONLY DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER WATER --- REMARKS: 302100Z POSITION NEAR 17.8S 178.3E. 30JAN21. TROPICAL CYCLONE 15P (ANA), LOCATED APPROXIMATELY 38 NM NORTH-NORTHWEST OF SUVA, FIJI, HAS TRACKED SOUTHEASTWARD AT 09 KNOTS OVER THE PAST SIX HOURS. ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY DEPICTS A RAPIDLY DEVELOPING SYSTEM, WITH DEEP SYMMETRICAL CONVECTION FORMING A CENTRAL DENSE OVERCAST OBSCURING THE LOW LEVEL CIRCULATION CENTER (LLCC). THE COMBINATION OF SURFACE OBSERVATIONS FROM RAKIRAKI (91669) AND VIWA ISLAND (91670, AS WELL AS ANIMATED RADAR DATA FROM FIJI WHICH DEPICTED A WEAK RADAR EYE, LENT HIGH CONFIDENCE TO THE INITIAL POSITION. BASED ON THE RADAR DATA, IT APPEARS THAT THE CENTER OF TC ANA CROSSED VERY CLOSE TO RAKIRAKI, SO THE 1800Z PRESSURE READING OF 978MB, WHICH CORRESPONDS TO ABOUT 60 KNOTS, LIKELY IS A VERY CLOSE ESTIMATION OF THE ACTUAL CENTER PRESSURE OF THE SYSTEM. THE INITIAL INTENSITY IS THUS ASSESSED AT 60 KNOTS WITH HIGH CONFIDENCE, HEDGED SLIGHTLY ABOVE A PGTW DVORAK CURRENT INTENSITY ESTIMATE OF T3.5 (55 KTS), CLOSER TO AN ADT ESIMATE OF T3.9 (63 KTS). UPPER-LEVEL ANALYSIS INDICATES FAVORABLE ENVIRONMENTAL CONDITIONS WITH LOW (5-10KT) VWS, AND STRONG OUTFLOW BOTH EQUATORWARD AND POLEWARD PROVIDED BY A SMALL POINT SOURCE WHICH HAS RECENTLY DEVELOPED OVER TOP OF THE SYSTEM, WHICH IS FIGHTING OFF THE PREDOMINANT WESTERLY SHEAR. SSTS (28-29C) ALSO REMAIN CONDUCIVE TO FURTHER DEVELOPMENT. IN THE NEAR-TERM, INTERACTION WITH THE VITU LEVU WILL LIMIT POTENTIAL INTENSIFCATION AND THUS INTENSITY IS FORECAST TO REMAIN STEADY THROUGH TAU 12. ONCE THE CENTER MOVES SOUTH OF THE MAIN ISLANDS, IT IS FORECAST TO AGAIN INTENSIFY, PEAKING AT 65 KNOTS BY TAU 24. AFTER THIS POINT, THE SYSTEM IS EXPECTED TO ACCELERATE SOUTHEASTWARD ALONG THE WESTERN PERIPHERY OF A DEEP-LAYER STR LOCATED TO THE EAST, WITH INCREASING VWS STEADILY, IF SLOWLY INCREASING. AFTER TAU 48 THE SYSTEM BEGINS TO MOVE OVER COOLER WATERS AND ENCOUNTERS HIGH (25-35 KT) VWS ASSOCIATED WITH STRONG MID-LATITUDE WESTERLY FLOW ALOFT. THE SYSTEM IS FORECAST TO DISSIPATE AS A TROPICAL CYCLONE AT OR BEFORE TAU 120. NUMERICAL MODEL GUIDANCE IS IN RELATIVELY GOOD CROSS-TRACK AGREEMENT, WITH 130NM SPREAD AT TAU 48, AND DECREASING THEREAFTER. HOWEVER, THERE ARE SIGNIFICANT ALONG-TRACK DIFFERENCES, PARTICUARLY AFTER TAU 72, AS WOULD BE EXPECTED FOR A SYSTEM MOVING RAPIDLY INTO THE SUBTROPICS, WITH UP TO 1300NM SPREAD AT TAU 120 BETWEEN THE GFS AND ECMWF. THE JTWC FORECAST TRACK LIES JUST EAST AND SLIGHTLY SLOWER THAN THE MULTI-MODEL CONSENSUS WITH HIGH CONFIDENCE THROUGH TAU 48 AND LOW CONFIDENCE THEREAFTER, AS ALONG-TRACK SPREAD INCREASES. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 301800Z IS 20 FEET. NEXT WARNINGS AT 310300Z, 310900Z, 311500Z AND 312100Z. REFER TO TROPICAL CYCLONE 16P (SIXTEEN) WARNINGS (WTPS32 PGTW) FOR SIX-HOURLY UPDATES.// NNNN