ABPW10 PGTW 210600 MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI// SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE WESTERN AND /SOUTH PACIFIC OCEANS/210600Z-220600ZDEC2020// REF/A/MSG/JOINT TYPHOON WRNCEN PEARL HARBOR HI/210151ZDEC2020// AMPN/REF A IS A TROPICAL CYCLONE WARNING.// RMKS/ 1. WESTERN NORTH PACIFIC AREA (180 TO MALAY PENINSULA): A. TROPICAL CYCLONE SUMMARY: (1) AT 21DEC20 0000Z, TROPICAL DEPRESSION 26W (KROVANH) WAS LOCATED NEAR 9.6N 113.6E, APPROXIMATELY 414 NM EAST OF HO CHI MINH CITY, VIETNAM, AND HAD TRACKED WEST- SOUTHWESTWARD AT 06 KNOTS OVER THE PAST SIX HOURS. MAXIMUM SUSTAINED SURFACE WINDS WERE ESTIMATED AT 30 KNOTS GUSTING TO 40 KNOTS. SEE REF A (WTPN31 PGTW 210300) FOR FURTHER DETAILS. (2) NO OTHER TROPICAL CYCLONES. B. TROPICAL DISTURBANCE SUMMARY: NONE. 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: (1) THE AREA OF CONVECTION (REMNANTS OF 05P) PREVIOUSLY LOCATED NEAR 23.9S 178.7E IS NOW LOCATED NEAR 24.8S 179.1E, APPROXIMATELY 305 NM SOUTHWEST OF TONGA. THE SYSTEM IS CURRENTLY CLASSIFIED AS A SUBTROPICAL STORM, GENERALLY CHARACTERIZED AS HAVING BOTH TROPICAL AND MID-LATITUDE CYCLONE FEATURES. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (EIR), SUPPORTED BY A 210430Z SSMI F- 15 85GHZ MICROWAVE IMAGE, DEPICTS A FULLY EXPOSED LOW LEVEL CIRCULATION CENTER (LLCC) WITH AN ASYMMETRIC OVERALL CONVECTIVE STRUCTURE AND THE MAJORITY OF THE DEEP CONVECTION OFFSET TO THE SOUTH. A 202142Z METOP-B ASCAT PASS REVEALS A THE TIGHT LLCC SURROUNDED BY 20 TO 25 KNOT WINDS TO THE NORTH AND A LARGE AREA OF 30 TO 35 KNOT WINDS TO THE SOUTH. THE VERTICAL CROSS-SECTION TEMPERATURE ANOMALY REVEALS A SURFACE WARM CORE BENEATH A COOL UPPER LEVEL CORE, FURTHER SUPPORTING THE CLASSIFICATION AS A SUBTROPICAL SYSTEM. THE REMNANTS OF 05P ARE CURRENTLY IN AN ENVIRONMENT UNFAVORABLE FOR TROPICAL DEVELOPMENT WITH EXCELLENT POLEWARD OUTFLOW BEING HEAVILY OFFSET BY UNFAVORABLE (40 TO 50 KNOT) VERTICAL WIND SHEAR AND COOL (<25 CELSIUS) SEA SURFACE TEMPERATURES. GLOBAL MODELS ARE IN GOOD AGREEMENT THAT THE REMNANTS OF 05P WILL TRACK SOUTH- SOUTHWESTWARD WHILE WEAKENING, EVENTUALLY DISSIPATING IN THE NEXT SEVERAL DAYS. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 30 TO 35 KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 996 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS REMAINS LOW. (2) NO OTHER SUSPECT AREAS.// NNNN