ABPW10 PGTW 170600 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE WESTERN AND SOUTH PACIFIC OCEANS/170600Z-180600ZJUL2021// REF/A/MSG/JOINT TYPHOON WRNCEN PEARL HARBOR/HI/170151ZJUL2021// AMPN/REF A IS A TROPICAL CYCLONE WARNING.// RMKS/ 1. WESTERN NORTH PACIFIC AREA (180 TO MALAY PENINSULA): A. TROPICAL CYCLONE SUMMARY: (1) AT 17JUL21 0000Z, TROPICAL DEPRESSION 09W (NINE) WAS LOCATED NEAR 20.5N 133.5E, APPROXIMATELY 477 NM SOUTHEAST OF KADENA AB, AND HAD TRACKED NORTHWESTWARD AT 08 KNOTS OVER THE PAST SIX HOURS. MAXIMUM SUSTAINED SURFACE WINDS WERE ESTIMATED AT 30 KNOTS GUSTING TO 40 KNOTS. SEE REF A (WTPN31 PGTW 170300) FOR FURTHER DETAILS. (2) NO OTHER TROPICAL CYCLONES. B. TROPICAL DISTURBANCE SUMMARY: (1) THE AREA OF CONVECTION (INVEST 99W) PREVIOUSLY LOCATED NEAR 18.8N 115.5E IS NOW LOCATED NEAR 18.4N 115.4E, APPROXIMATELY 245 NM SOUTH-SOUTHEAST OF HONG KONG. ANIMATED MULTISPECTRAL SATELLITE IMAGERY DEPICTS BROAD TURNING WITH FORMATIVE CONVECTIVE BANDING OVER THE NORTHEAST QUADRANT. A 170232Z METOP-B ASCAT IMAGE REVEALS 15KT WIND BARBS IN THE NORTHERN SEMICIRCLE AND WEAKER WINDS ELSEWHERE, WRAPPING INTO A BROAD LOW LEVEL CIRCULATION CENTER (LLCC). ENVIRONMENTAL ANALYSIS INDICATES FAVORABLE CONDITIONS WITH GOOD WESTWARD OUTFLOW ALOFT, LOW (5-10 KTS) VERTICAL WIND SHEAR AND WARM (31-32C) SEA SURFACE TEMPERATURES. GFS AND ICON BOTH INDICATE INVEST 99W WILL CONSOLIDATE AND INTENSIFY AS IT TRACKS TO THE WEST- NORTHWEST OVER THE NEXT 24-48 HOURS. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 15 TO 20 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 UPGRADED TO MEDIUM. (2) NO OTHER SUSPECT AREAS. C. SUBTROPICAL SYSTEM SUMMARY: NONE. 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