ABPW10 PGTW 010130 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE WESTERN AND SOUTH PACIFIC OCEANS REISSUED/010130Z-010600ZSEP2026// REF/A/MSG/JOINT TYPHOON WRNCEN PEARL HARBOR HI/310721ZAUG2026// REF/B/MSG/JOINT TYPHOON WRNCEN PEARL HARBOR HI/010121ZSEP2026// NARR/REFS A AND B ARE TROPICAL CYCLONE FORMATION ALERTS.// RMKS/ 1. WESTERN NORTH PACIFIC AREA (180 TO MALAY PENINSULA): A. TROPICAL CYCLONE SUMMARY: NONE. B. TROPICAL DISTURBANCE SUMMARY: (1) THE AREA OF CONVECTION (INVEST 94W) PREVIOUSLY LOCATED NEAR 20.6N 133.3E IS NOW LOCATED NEAR 21.6N 132.7E, APPROXIMATELY 268 NM SOUTH-SOUTHEAST OF MINAMI DAITO JIMA. THE SYSTEM IS CURRENTLY CLASSIFIED AS A MONSOON DEPRESSION, GENERALLY CHARACTERIZED AS A LARGE CYCLONIC CIRCULATION, GREATER THAN 600NM DIAMETER, WITH ELEVATED WINDS OVER THE SOUTHEASTERN PERIPHERY AND A WEAK CORE OF LIGHT WINDS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS A PARTIALLY EXPOSED, BROAD AND ELONGATED LOW-LEVEL CIRCULATION CENTER (LLCC), WITH A LARGE WIND FIELD AND PERSISTENT CONVECTION ALONG BOTH ENDS OF THE CIRCULATION. THE SYSTEM IS LOCATED ALONG THE MONSOON TROUGH, WHICH EXTENDS FROM TAIWAN TO THE MARIANA ISLANDS. OVER THE NEXT 12-24 HOURS, THE CENTER OF THE LLCC WILL BE PRONE TO SHIFTING ALONG THIS TROUGH AXIS, EITHER TOWARD THE WEST AND CLOSER TO OKINAWA OR EAST AND FURTHER AWAY. THE ENVIRONMENTAL ANALYSIS OF THE AREA INDICATES FAVORABLE CONDITIONS FOR DEVELOPMENT WITH LOW (10-15 KTS) VERTICAL WIND SHEAR (VWS), WARM (29-30 C) SEA SURFACE TEMPERATURES, AND STRONG EQUATORWARD OUTFLOW IN THE UPPER LEVELS, OFFSET BY A NARROW BAND OF DRY AIR SEPARATING THE MOIST WESTERLY FLOW FROM THE CIRCULATION. THE RADIUS OF MAXIMUM WINDS IS CURRENTLY OVER 100 NM. HOWEVER, ONLY A SLIGHT TIGHTENING OF THE WIND FIELD IS NEEDED TO DESIGNATE THE SYSTEM AS A TROPICAL DEPRESSION. WHILE GLOBAL DETERMINISTIC AND ENSEMBLE MODELS AGREE ON GRADUAL CONSOLIDATION AS THE SYSTEM REMAINS GENERALLY QUASI- STATIONARY, THE PRECISE FORMATION LOCATION ALONG THE TROUGH AXIS REMAINS LESS CERTAIN. FOR HAZARDS AND WARNINGS, REFERENCE THE FLEET WEATHER CENTER SAN DIEGO HIGH WINDS AND SEAS PRODUCT OR REFER TO LOCAL WMO DESIGNATED FORECAST AUTHORITY. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 23 TO 28 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1001 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS REMAINS HIGH. SEE REF A (WTPN21 PGTW 310730) FOR FURTHER DETAILS. (2) THE AREA OF CONVECTION (INVEST 96W) PREVIOUSLY LOCATED NEAR 22.7N 117.8E IS NOW LOCATED NEAR 21.9N 117.3E, APPROXIMATELY 229 NM SOUTHWEST OF TAIPEI, TAIWAN. ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS AN ELONGATED TROUGH WITH SPORADIC BURSTS OF CONVECTION BUT NO DEFINED LOW-LEVEL CIRCULATION CENTER. ENVIRONMENTAL ANALYSIS REVEALS MODERATELY UNFAVORABLE CONDITIONS FOR DEVELOPMENT WITH POOR UPPER- LEVEL OUTFLOW, LOW VERTICAL WIND SHEAR (10-15 KTS), AND WARM SEA SURFACE TEMPERATURES (28-29 C). THE SOUTHWESTERLY MONSOON FLOW APPROACHING SOUTHEAST COAST OF CHINA AND THROUGH THE TAIWAN STRAIT HAS WASHED OUT THE PREVIOUSLY OBSERVED WEAK SURFACE CIRCULATION. THE DETERMINISTIC MODELS NO LONGER DEPICT CONSOLIDATION OF 96W AND ENSEMBLE HAS BEEN REDUCED TO ONLY A HANDFUL OF MEMBERS OVER THE NEXT 48 HOURS. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 13 TO 18 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1002 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS DOWNGRADED TO LOW. (3) THE AREA OF CONVECTION (INVEST 17W) PREVIOUSLY LOCATED NEAR 20.1N 110.2E IS NOW LOCATED NEAR 19.5N 112.9E, APPROXIMATELY 183 NM SOUTH-SOUTHWEST OF HONG KONG. ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS AN ELONGATED LOW-LEVEL CIRCULATION WITH FLARING CONVECTION ALONG THE EASTERN PERIPHERY. ENVIRONMENTAL ANALYSIS REVEALS FAVORABLE CONDITIONS FOR DEVELOPMENT WITH STRONG EQUATORWARD UPPER-LEVEL WINDS, LOW VERTICAL WIND SHEAR (10-15 KTS), AND WARM SEA SURFACE TEMPERATURES (28-29 C). GLOBAL MODELS AGREE ON 17W TRACKING GENERALLY NORTHEASTWARD AS IT CONSOLIDATES OVER THE NEXT 24-48 HOURS. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 23 TO 28 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1001 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS UPGRADED TO HIGH. SEE REF B (WTPN22 PGTW 010130) FOR FURTHER DETAILS. (4) NO OTHER SUSPECT AREAS. C. SUBTROPICAL SYSTEM SUMMARY: (1) THE AREA OF CONVECTION (INVEST 20W) PREVIOUSLY LOCATED NEAR 44.1N 169.6E HAS DISSIPATED AND IS NO LONGER SUSPECT FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE IN THE NEXT 24 HOURS. (2) AN AREA OF CONVECTION (REMNANTS 21W) HAS PERSISTED NEAR 34.9N 167.7E, APPROXIMATELY 867 NM WEST-NORTHWEST OF MIDWAY ISLAND. THE SYSTEM IS CURRENTLY CLASSIFIED AS A SUBTROPICAL DEPRESSION, GENERALLY CHARACTERIZED AS HAVING BOTH TROPICAL AND MIDLATITUDE CYCLONE FEATURES. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY SHOWS A COMPACT, FULLY EXPOSED LOW-LEVEL CIRCULATION CENTER. ENVIRONMENTAL ANALYSIS DEPICTS UNFAVORABLE CONDITIONS FOR DEVELOPMENT WITH POOR UPPER-LEVEL OUTFLOW, HIGH VERTICAL WIND SHEAR (25-30 KTS), AND COOL SEA SURFACE TEMPERATURES (25-26 C). ALL DETERMINISTIC AND ENSEMBLE GUIDANCE SUGGEST THERE IS A VERY LOW LIKELIHOOD OF 21W REDEVELOPING ANY TROPICAL CHARACTERISTICS AS IT QUICKLY TRANSITS NORTHWARD IN THE MID-LATITUDE BAROCLINIC ZONE. FOR HAZARDS AND WARNINGS, REFERENCE THE FLEET WEATHER CENTER SAN DIEGO HIGH WINDS AND SEAS PRODUCT OR REFER TO LOCAL WMO DESIGNATED FORECAST AUTHORITY. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 28 TO 33 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1001 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS LOW. (3) NO OTHER SUBTROPICAL SYSTEMS. 2. SOUTH PACIFIC AREA (WEST COAST OF SOUTH AMERICA TO 135 EAST): A. TROPICAL CYCLONE SUMMARY: NONE. B. TROPICAL DISTURBANCE SUMMARY: NONE. C. SUBTROPICAL SYSTEM SUMMARY: NONE. 3. JUSTIFICATION FOR REISSUE: UPGRADED AREA IN PARA. 1.B.(3) TO HIGH, DOWNGRADED AREA IN PARA. 1.B.(2) TO LOW, DISSIPATED AREA IN 1.C.(1).// NNNN