ABIO10 PGTW 211800
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE INDIAN 
OCEAN/211800Z-221800ZOCT2025//
REF/A/MSG/JOINT TYPHOON WRNCEN PEARL HARBOR HI/210751ZOCT2025//
AMPN/REF A IS A TROPICAL CYCLONE WARNING.//
RMKS/
1. NORTH INDIAN OCEAN AREA (MALAY PENINSULA WEST TO COAST OF AFRICA):
   A. TROPICAL CYCLONE SUMMARY: NONE.
   B. TROPICAL DISTURBANCE SUMMARY:
      (1) AN AREA OF CONVECTION (INVEST 92A) HAS PERSISTED NEAR 8.7N 
67.8E, APPROXIMATELY 684 NM SOUTH-SOUTHWEST OF MUMBAI, INDIA. ANIMATED 
ENHANCED INFRARED IMAGERY (EIR) AND A 211654Z METOP-B ASCAT PASS 
DEPICT A BROAD AND POORLY ORGANIZED CIRCULATION EMBEDDED WITHIN 
FLARING CONVECTION IN THE NORTHWESTERN PERIPHERY. ENVIRONMENTAL 
ANALYSIS REVEALS MARGINALLY FAVORABLE CONDITIONS, WITH WARM (28-29 C) 
SEA SURFACE TEMPERATURES AND WESTWARD AND POLEWARD OUTFLOW ALOFT 
OFFSET BY MODERATE TO HIGH (20-25 KTS) EASTERLY VERTICAL WIND SHEAR. 
GLOBAL DETERMINISTIC MODELS SHOW A VERY SLOW AND GRADUAL DEVELOPMENT 
OVER TIME, WITH THE NAVGEM SOLUTION THE MOST DISTINCT AND FASTEST. 
ENSEMBLE MODELS ARE IN GENERAL AGREEMENT REGARDING A GRADUAL BUILD IN 
THE WIND SPEED UP TO 35 KTS OVER THE NEXT SEVERAL DAYS. MAXIMUM 
SUSTAINED SURFACE WINDS ARE ESTIMATED AT 18 TO 22 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 LOW.
      (2) NO OTHER SUSPECT AREAS.
   C. SUBTROPICAL SYSTEM SUMMARY: NONE.
2. SOUTH INDIAN OCEAN AREA (135E WEST TO COAST OF AFRICA):
   A. TROPICAL CYCLONE SUMMARY:
      (1) AT 21OCT25 0600Z, TROPICAL CYCLONE 04S (CHENGE) WAS LOCATED 
NEAR 9.6S 65.2E, APPROXIMATELY 459 NM WEST-SOUTHWEST OF DIEGO GARCIA, 
AND HAD TRACKED WESTWARD AT 12 KNOTS OVER THE PAST SIX HOURS. MAXIMUM 
SUSTAINED SURFACE WINDS WERE ESTIMATED AT 60 KNOTS GUSTING TO 75 
KNOTS. SEE REF A (WTXS31 PGTW 210900) FOR FURTHER DETAILS.
      (2) NO OTHER TROPICAL CYCLONES.
   B. TROPICAL DISTURBANCE SUMMARY:
      (1) THE AREA OF CONVECTION (INVEST 95S) PREVIOUSLY LOCATED NEAR 
4.6S 97.6E IS NOW LOCATED NEAR 6.3S 94.5E, APPROXIMATELY 377 NM NORTH-
NORTHWEST OF THE COCOS ISLANDS. ANIMATED ENHANCED INFRARED IMAGERY 
(EIR) AND A 211508Z METOP-B ASCAT PASS DEPICT A BROAD AND SLOWLY 
CONSOLIDATING CIRCULATION WITH ASSOCIATED DEEP CONVECTION NEAR THE 
LOW-LEVEL CIRCULATION CENTER AND OVER THE SOUTHWESTERN PERIPHERY. 
ENVIRONMENTAL ANALYSIS REVEALS MARGINALLY FAVORABLE CONDITIONS FOR 
DEVELOPMENT WITH LOW TO MODERATE NORTHEASTERLY VERTICAL WIND SHEAR 
(15-20 KTS), RADIAL OUTFLOW, AND WARM SEA SURFACE TEMPERATURES (29-30 
C). GLOBAL DETERMINISTIC MODELS HAVE A TRACEABLE CIRCULATION BUT ARE 
NOT SHOWING MUCH DEVELOPMENT OVER THE NEXT 24-48 HOURS AS THE SYSTEM 
TRACKS WEST-SOUTHWESTWARD. HOWEVER, THE NUMBER OF GEFS AND EC-ENS 
ENSEMBLE MODEL MEMBERS REACHING WARNING THRESHOLDS WITHIN THE NEXT 1-2 
DAYS HAS INCREASED A BIT IN RECENT RUNS. MAXIMUM SUSTAINED SURFACE 
WINDS ARE ESTIMATED AT 23 TO 27 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 REMAINS MEDIUM.
      (2) NO OTHER SUSPECT AREAS.
   C. SUBTROPICAL SYSTEM SUMMARY: NONE.//
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