South Pacific Tropical Cyclone Tracking

ABPW10 PGTW 210600
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE WESTERN AND SOUTH 
PACIFIC OCEANS 210600Z-220600ZDEC2024//
REF/A/MSG/JOINT TYPHOON WRNCEN PEARL HARBOR HI/210551ZDEC2024//
REF/B/MSG/JOINT TYPHOON WRNCEN PEARL HARBOR HI/210552ZDEC2024//
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 98W) PREVIOUSLY LOCATED NEAR 
4.3N 113.0E IS NOW LOCATED NEAR 4.4N 112.8E, APPROXIMATELY 259 NM 
WEST OF BRUNEI. ANIMATED MULTISPECTRAL SATELLITE IMAGERY AND A 
202305Z SSMIS 91GHZ MICROWAVE IMAGE DEPICT A MORE SYMMETRIC 
CIRCULATION, WITH FRAGMENTED, FORMATIVE BANDING ORGANIZING AROUND THE 
CIRCULATION, AND DEEP CONVECTION BUILDING OVER THE CENTER. 
ADDITIONALLY, A 210204Z ASCAT PASS SHOWS 15 KNOTS WRAPPING AROUND THE 
CIRCULATION, WITH STRONGER 30 KNOT WINDS LOCATED AROUND THE SOUTHWEST 
PERIPHERY. ENVIRONMENTAL ANALYSIS REVEALS THAT INVEST 98W IS IN A 
FAVORABLE ENVIRONMENT FOR FURTHER DEVELOPMENT, WITH WARM (29-30C) SEA 
SURFACE TEMPERATURES, GOOD POLEWARD OUTFLOW ALOFT, OFFSET BY MODERATE 
TO HIGH VERTICAL WIND SHEAR (20-25KTS). GLOBAL MODELS ARE IN GOOD 
AGREEMENT THAT INVEST 98W WILL GENERALLY TRACK POLEWARD OVER THE NEXT 
36 HOURS. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 18 TO 23 
KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1005 MB. 
THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE 
WITHIN THE NEXT 24 HOURS IS UPGRADED TO HIGH. SEE REF A (WTPN21 PGTW 
210600) 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: NONE.
   B. TROPICAL DISTURBANCE SUMMARY:
      (1) THE AREA OF CONVECTION (INVEST 96P) PREVIOUSLY LOCATED 
NEAR 18.6S 147.5E IS NOW LOCATED NEAR 19.0S 149.4E, APPROXIMATELY 247 
NM EAST-SOUTHEAST OF CAIRNS, AUSTRALIA. ANIMATED MULTISPECTRAL 
SATELLITE IMAGERY DEPICTS A BROAD LOW-LEVEL CIRCULATION CENTER 
(LLCC), WITH DEEP CONVECTION SHEARED OVER THE EASTERN QUADRANT. A 
202348Z ASCAT-C IMAGE REVEALS PRIMARILY 15-25 KNOT WINDS AROUND THE 
PERIPHERY OF THE ELONGATED CIRCULATION, WITH A LIMITED REGION OF 30-
35 KNOT WINDS OVER THE EASTERN QUADRANT ASSOCIATED WITH THE 
PERSISTENT DEEP CONVECTION. ANIMATED RADAR IMAGERY FROM THE 
TOWNSVILLE RADAR SHOWS FAIRLY DISORGANIZED DEEP CONVECTION ALONG THE 
PERIPHERY OF THE LLCC. SURFACE OBSERVATIONS FROM CREAL REEF INDICATE 
25-30 KNOT SUSTAINED EASTERLY (10-MINUTE AVERAGE) WINDS, WHICH IS 
CONSISTENT WITH RECENT ASCAT DATA. SOUTHEASTERLY WINDS ALONG THE 
EASTERN COAST OF AUSTRALIA ARE SIGNIFICANTLY LOWER, RANGING FROM 15 
TO 25 KNOTS. INVEST 96P IS LOCATED UNDER MODERATE SUBTROPICAL 
WESTERLIES, WITH LOW TO MODERATE (15-20 KNOTS) VERTICAL WIND SHEAR. 
GLOBAL MODELS INDICATE A QUICK EASTWARD TO EAST-SOUTHEASTWARD TRACK 
AND A SHORT WINDOW FOR WARM-CORE DEVELOPMENT BEFORE THE SYSTEM 
TRANSITIONS INTO A SUBTROPICAL STORM. MAXIMUM SUSTAINED SURFACE WINDS 
ARE ESTIMATED AT 30 TO 35 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 IS UPGRADED TO 
HIGH. SEE REF A (WTPS21 PGTW 210600) FOR FURTHER DETAILS. 
      (2) NO OTHER SUSPECT AREAS.
   C. SUBTROPICAL SYSTEM SUMMARY: NONE.
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