ABIO10 PGTW 311800
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE INDIAN 
OCEAN/311800ZJAN2025-011800ZFEB2025//
REF/A/MSG/JOINT TYPHOON WRNCEN PEARL HARBOR HI/311351ZJAN2025//
REF/B/MSG/JOINT TYPHOON WRNCEN PEARL HARBOR HI/310752ZJAN2025//
NARR/REFS A AND B ARE TROPICAL CYCLONE WARNINGS.//
RMKS/
1. NORTH INDIAN OCEAN AREA (MALAY PENINSULA WEST TO COAST OF AFRICA):
   A. TROPICAL CYCLONE SUMMARY: NONE.
   B. TROPICAL DISTURBANCE SUMMARY: NONE.
   C. SUBTROPICAL SYSTEM SUMMARY: NONE.
2. SOUTH INDIAN OCEAN AREA (135E WEST TO COAST OF AFRICA):
   A. TROPICAL CYCLONE SUMMARY:
      (1) AT 31JAN25 1200Z, TROPICAL CYCLONE 11S (ELEVEN) WAS LOCATED 
NEAR 16.9S 65.6E, APPROXIMATELY 510 NM EAST-NORTHEAST OF PORT LOUIS, 
MAURITIUS, AND HAD TRACKED SOUTHWESTWARD AT 15 KNOTS OVER THE PAST SIX 
HOURS. MAXIMUM SUSTAINED SURFACE WINDS WERE ESTIMATED AT 35 KNOTS 
GUSTING TO 45 KNOTS. SEE REF A (WTXS31 PGTW 311500) FOR FURTHER 
DETAILS.
      (2) AT 31JAN25 0600Z, TROPICAL CYCLONE 12S (ELVIS) WAS LOCATED 
NEAR 31.7S 48.5E, APPROXIMATELY 722 NM SOUTHEAST OF EUROPA ISLAND, AND 
HAD TRACKED SOUTHEASTWARD AT 13 KNOTS OVER THE PAST SIX HOURS. MAXIMUM 
SUSTAINED SURFACE WINDS WERE ESTIMATED AT 40 KNOTS GUSTING TO 50 
KNOTS. SEE REF B (WTXS32 PGTW 310900) FOR FURTHER DETAILS.
      (3) NO OTHER TROPICAL CYCLONES.
   B. TROPICAL DISTURBANCE SUMMARY:
      (1) THE AREA OF CONVECTION (INVEST 99S) PREVIOUSLY LOCATED NEAR 
14.6S 105.7E IS NOW LOCATED NEAR 14.7S 105.4E, APPROXIMATELY 519 NM 
SOUTHEAST OF COCOS ISLANDS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY 
(MSI) DEPICTS AN AREA OF LOW-LEVEL ROTATION WITH FLARING CONVECTION 
BEGINNING TO FORM JUST NORTH OF THE CENTER. A 311453Z ASCAT METOP-C 
25KM PARTIAL PASS SHOWS 15-20 KNOT NORTH-WESTERLY WINDS ALONG THE 12S 
LATITUDE THAT ARE HELPING 99S GAIN MORE MOMENTUM. ENVIRONMENTAL 
ANALYSIS INDICATES THAT INVEST 99S IS IN A FAVORABLE ENVIRONMENT FOR 
FURTHER DEVELOPMENT DUE TO WARM (29-30C) SEA SURFACE TEMPERATURES, 
GOOD POLEWARD OUTFLOW ALOFT, AND IS CURRENTLY IN AN AREA OF LOW TO 
MODERATE (15 TO 20 KNOTS) VERTICAL WIND SHEAR. GLOBAL MODELS ARE IN 
AGREEMENT THAT INVEST 99S WILL CONTINUE TO CONSOLIDATE AND TAKE A 
SOUTHWESTWARD TRACK OVER THE NEXT 24 HOURS. MAXIMUM SUSTAINED SURFACE 
WINDS ARE ESTIMATED AT 23 TO 28 KNOTS. MINIMUM SEA LEVEL PRESSURE IS 
ESTIMATED TO BE NEAR 1000 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A 
SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS REMAINS MEDIUM.
      (2) THE AREA OF CONVECTION (INVEST 90S) PREVIOUSLY LOCATED NEAR 
12.5S 120.0E IS NOW LOCATED NEAR 13.4S 120.5E, APPROXIMATELY 290 NM 
NORTH-NORTHWEST OF BROOME, AUSTRALIA. ANIMATED MULTISPECTRAL SATELLITE 
IMAGERY (MSI) DEPICTS AN ELONGATED LLCC EMBEDDED WITHIN PERSISTENT 
DEEP CONVECTION OVERTOP. A STRONG BELT OF WESTERLY FLOW (20-25 KNOTS) 
ALONG THE NORTHERN PERIPHERY OF THE CIRCULATION WILL CONTINUE TO HELP 
INVEST 90S GAIN INTENSITY OVER THE NEXT 24 HOURS.  ENVIRONMENTAL 
ANALYSIS INDICATES THAT INVEST 90S IS IN A FAVORABLE ENVIRONMENT FOR 
FURTHER DEVELOPMENT DUE TO VERY WARM (30-31C) SEA SURFACE 
TEMPERATURES, MODERATE DUAL CHANNEL OUTFLOW ALOFT, AND LOW TO MODERATE 
(15 TO 20 KNOTS) VERTICAL WIND SHEAR. GLOBAL MODELS ARE IN GOOD 
AGREEMENT THAT INVEST 90S WILL QUICKLY CONSOLIDATE AND TRACK 
SOUTHWESTWARD OVER THE NEXT 24 HOURS. MAXIMUM SUSTAINED SURFACE WINDS 
ARE ESTIMATED AT 23 TO 28 KNOTS. MINIMUM SEA LEVEL PRESSURE IS 
ESTIMATED TO BE NEAR 1001 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A 
SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS UPGRADED TO 
MEDIUM.
      (3) NO OTHER SUSPECT AREAS.
   C. SUBTROPICAL SYSTEM SUMMARY: NONE.//
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