ABPW10 PGTW 230600 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE WESTERN AND /SOUTH PACIFIC OCEANS/230600Z-240600ZJUL2021// REF/A/MSG/JOINT TYPHOON WRNCEN PEARL HARBOR HI/230152ZJUL2021// REF/B/MSG/JOINT TYPHOON WRNCEN PEARL HARBOR HI/230151ZJUL2021// REF/C/MSG/JOINT TYPHOON WRNCEN PEARL HARBOR HI/222151ZJUL2021// NARR/REFS A AND B ARE TROPICAL CYCLONE WARNINGS. REF C IS A /TROPICAL CYCLONE FORMATION ALERT.// RMKS/ 1. WESTERN NORTH PACIFIC AREA (180 TO MALAY PENINSULA): A. TROPICAL CYCLONE SUMMARY: (1) AT 23JUL21 0000Z, TROPICAL DEPRESSION 10W (CEMPAKA) WAS LOCATED NEAR 20.8N 107.4E, APPROXIMATELY 85 NM EAST OF HANOI, VIETNAM, AND HAD TRACKED SOUTHWARD AT 06 KNOTS OVER THE PAST SIX HOURS. MAXIMUM SUSTAINED SURFACE WINDS WERE ESTIMATED AT 25 KNOTS GUSTING TO 35 KNOTS. SEE REF A (WTPN32 PGTW 230300) FOR FURTHER DETAILS. (2) AT 23JUL21 0000Z, TYPHOON 09W (IN-FA) WAS LOCATED NEAR 24.1N 125.3E, APPROXIMATELY 198 NM SOUTHWEST OF KADENA AB, AND HAD TRACKED NORTH-NORTHWESTWARD AT 04 KNOTS OVER THE PAST SIX HOURS. MAXIMUM SUSTAINED SURFACE WINDS WERE ESTIMATED AT 75 KNOTS GUSTING TO 90 KNOTS. SEE REF B (WTPN31 PGTW 230300) FOR FURTHER DETAILS. (3) NO OTHER TROPICAL CYCLONES. B. TROPICAL DISTURBANCE SUMMARY: NONE. C. SUBTROPICAL SYSTEM SUMMARY: (1) THE AREA OF CONVECTION (INVEST 90W) PREVIOUSLY LOCATED NEAR 21.7N 144.7E IS NOW LOCATED NEAR 23.2N 148.3E, APPROXIMATELY 854 NM SOUTHEAST OF YOKOSUKA, JAPAN. ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS A LOW LEVEL CIRCULATION CENTER (LLCC) LOCATED IN THE SOUTHERN EDGE OF A DEEP UPPER LEVEL TROUGH WITH DEEP CONVECTION OFFSET TO THE EASTERN AND SOUTHEASTERN PERIPHERIES. A 230025Z ASCAT-B DIRECT PASS DEPICTS A WELL DEFINED LLCC WITH 20-25 KT WIND BARBS IN THE EASTERN SEMICIRCLE WITH LOWER WIND BARBS IN THE WESTERN SEMICIRCLE. ENVIRONMENTAL ANALYSIS INDICATES INVEST 90W IS LOCATED IN THE DIVERGENT PORTION OF THE AFORMENTIONED TROUGH WITH UPPER LEVEL VENTING ASSOCIATED WITH THE SUBTROPICAL JET TO THE NORTHEAST. FURTHER ANALYSIS SHOWS INVEST 90W IS LOCATED UNDER TIGHT VERTICAL WIND SHEAR OF 20-30 KT AND WARM (29-30C) SEA SURFACE TEMPERATURES (SST). THIS DISTURBANCE IS EXPECTED TO DEVELOP QUICKLY AS A SUBTROPICAL CYCLONE AND IS FORECASTED TO INTENSIFY AS IT TRACKS NORTHEASTWARD WITHIN A DEEP UPPER-LEVEL TROUGH WITH WEAK BAROCLINICITY. GLOBAL MODELS INDICATE THAT AS THE SYSTEM TRACKS TOWARD CENTRAL HONSHU, THE SYSTEM WILL TRANSITION TO A WARM-CORE TROPICAL SYSTEM EAST OF THE KANTO PLAIN. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 20 TO 25 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 998 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS REMAINS HIGH. SEE REF C (WTPN21 PGTW 222200) FOR FURTHER DETAILS. (2) 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.// NNNN