ABPW10 PGTW 182100 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE WESTERN AND /SOUTH PACIFIC OCEANS REISSUED/182100Z-190600ZDEC2020// REF/A/MSG/JOINT TYPHOON WRNCEN PEARL HARBOR HI/181951ZDEC2020// REF/B/MSG/JOINT TYPHOON WRNCEN PEARL HARBOR HI/182021ZDEC2020// NARR/REF A IS A TROPICAL CYCLONE WARNING. REF B IS A TROPICAL /CYCLONE FORMATION ALERT.// 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 99W) PREVIOUSLY LOCATED NEAR 6.8N 126.3E IS NOW LOCATED NEAR 8.7N 123.2E, APPROXIMATELY 311NM EAST-SOUTHEAST OF PUERTO PRINCESA, PHILIPPINES. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY AND AN 181736Z AMSR2 GW1 89GHZ MICROWAVE IMAGE DEPICT A SLOWLY CONSOLIDATING LOW LEVEL CIRCULATION (LLC) WITH FLARING CONVECTION SHEARED TO THE NORTHWEST QUADRANT. UPPER LEVEL ANALYSIS REVEALS THAT 99W IS IN A MARGINALLY FAVORABLE ENVIRONMENT FOR DEVELOPMENT WITH WARM SST (28-29C), MODERATE VERTICAL WIND SHEAR (15-20 KNOTS), AND STRONG POLEWARD OUTFLOW. GLOBAL MODELS INDICATE THE SYSTEM WILL INTENSIFY AS IT BEGINS TO TAP INTO A NORTHEAST SURGE EVENT AS THE SYSTEM CONTINUES TO TRACK WEST- NORTHWESTWARD. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 20 TO 25 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1004 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS UPGRADED TO HIGH. SEE REF B (WTPN21 PGTW 182030) FOR FURTHER DETAILS. (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: (1) AT 18DEC20 1800Z, TROPICAL CYCLONE 05P (YASA) WAS LOCATED NEAR 20.3S 178.0W, APPROXIMATELY 243 NM EAST-SOUTHEAST OF SUVA, FIJI, AND HAD TRACKED SOUTHWARD AT 08 KNOTS OVER THE PAST SIX HOURS. MAXIMUM SUSTAINED SURFACE WINDS WERE ESTIMATED AT 60 KNOTS GUSTING TO 75 KNOTS. SEE REF A (WTPS31 PGTW 182100) FOR FURTHER DETAILS. (2) NO OTHER TROPICAL CYCLONES. B. TROPICAL DISTURBANCE SUMMARY: NONE. C. SUBTROPICAL SYSTEM SUMMARY: NONE. 3. JUSTIFICATION FOR REISSUE: UPGRADED AREA IN 1.B.(1) TO HIGH.// NNNN