ABIO10 PGTW 301800
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE INDIAN 
OCEAN/301800ZSEP2025-011800ZOCT2025//
REF/A/MSG/JOINT TYPHOON WRNCEN PEARL HARBOR HI/301752ZSEP2025//
AMPN/REF A IS A TROPICAL CYCLONE FORMATION ALERT.//
RMKS/
1. NORTH INDIAN OCEAN AREA (MALAY PENINSULA WEST TO COAST OF AFRICA):
   A. TROPICAL CYCLONE SUMMARY: NONE.
   B. TROPICAL DISTURBANCE SUMMARY:
      (1) THE AREA OF CONVECTION (INVEST 90A) PREVIOUSLY LOCATED NEAR 
23.5N 70.0E IS NOW LOCATED NEAR 22.0N 68.9E, APPROXIMATELY 199 NM 
SOUTH-SOUTHEAST OF KARACHI. ANIMATED ENHANCED INFRARED (EIR) 
SATELLITE IMAGERY DEPICTS A PARTIALLY EXPOSED LOW-LEVEL CIRCULATION, 
WITH DEEP CONVECTION SHEARED TO THE WEST. A 301549Z ASCAT-B PASS 
SHOWS AN ELONGATED CIRCULATION WITH A SWATH OF 20-25 KNOT WINDS OVER 
THE SOUTHERN SEMICIRCLE OF THE CIRCULATION. A 301327Z WSFM 89 GHZ 
MICROWAVE IMAGE SHOWS A WEAK LOW-LEVEL CIRCULATION WITH SHALLOW 
BANDING OVER THE SOUTHERN SEMICIRCLE OF THE SYSTEM. ENVIRONMENTAL 
ANALYSIS DEPICTS A FAVORABLE ENVIRONMENT FOR DEVELOPMENT WITH LOW 
VERTICAL WIND SHEAR OF 5-10 KNOTS, GOOD UPPER-LEVEL EQUATORWARD 
OUTFLOW, AND WARM SEA SURFACE TEMPERATURES (SST) OF 28-29 KNOTS. 
DETERMINISTIC AND ENSEMBLE MODELS AGREE ON THE SYSTEM HAVING A 
GENERAL WEST-SOUTHWESTWARD TRACK BUT DISAGREE ON THE INTENSITY OF THE 
SYSTEM AS WELL AS THE TIMELINE OF FORMATION. MAXIMUM SUSTAINED 
SURFACE WINDS ARE ESTIMATED AT 23 TO 28 KNOTS. MINIMUM SEA LEVEL 
PRESSURE IS ESTIMATED TO BE NEAR 999 MB. THE POTENTIAL FOR THE 
DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 
HOURS REMAINS LOW.
      (2) THE AREA OF CONVECTION (INVEST 91B) PREVIOUSLY LOCATED NEAR 
15.6N 89.6E IS NOW LOCATED NEAR 14.8N 86.7E, APPROXIMATELY 265 NM 
SOUTHEAST OF VISAKHAPATNAM. ANIMATED MULTISPECTRAL SATELLITE IMAGERY 
REVEALS A CONSOLIDATING LOW LEVEL CIRCULATION (LLC) WITH IMPROVED 
CONVECTIVE BANDING. A 301546Z ASCAT-B PASS INDICATES A SWATH OF 35 
KNOT NORTHERLY WINDS NEAR THE WESTERN PERIPHERY. ENVIRONMENTAL 
ANALYSIS SHOWS A FAVORABLE ENVIRONMENT FOR DEVELOPMENT WITH LOW 
VERTICAL WIND SHEAR OF 5-10 KNOTS, EQUATORWARD UPPER-LEVEL OUTFLOW, 
AND WARM SEA SURFACE TEMPERATURES OF 28-29 C. GLOBAL MODELS AGREE ON 
THE SYSTEM HAVING A GENERAL NORTH-NORTHWESTWARD TRACK WITH STEADY 
DEVELOPMENT AND INTENSIFICATION IN THE NEXT 12-36 HOURS. MAXIMUM 
SUSTAINED SURFACE WINDS ARE ESTIMATED AT 25 TO 30 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 (WTIO21 PGTW 301800) FOR FURTHER 
DETAILS.
      (3) NO OTHER SUSPECT AREAS.
   C. SUBTROPICAL SYSTEM SUMMARY: NONE.
2. SOUTH INDIAN OCEAN AREA (135E WEST TO COAST OF AFRICA):
   A. TROPICAL CYCLONE SUMMARY: NONE.
   B. TROPICAL DISTURBANCE SUMMARY: NONE.
   C. SUBTROPICAL SYSTEM SUMMARY: NONE.//
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