ABIO10 PGTW 190100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE INDIAN OCEAN 
REISSUED/190100Z-191800ZFEB2026//
REF/A/MSG/JOINT TYPHOON WRNCEN PEARL HARBOR HI/190051ZFEB2026// 
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: NONE.
   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:
      (1) THE AREA OF CONVECTION (INVEST 97S) PREVIOUSLY LOCATED NEAR 
12.5S 76.1E IS NOW LOCATED NEAR 12.9S 76.3E, APPROXIMATELY 401 NM 
SOUTHEAST OF DIEGO GARCIA. ANIMATED ENHANCED INFRARED SATELLITE 
IMAGERY (EIR) DEPICTS A PARTIALLY EXPOSED LOW-LEVEL CIRCULATION CENTER 
(LLCC) LOCATED APPROXIMATELY 400 NM SOUTHEAST OF DIEGO GARCIA. DEEP 
CONVECTION HAS BEEN PATCHY WITH LIMITED COVERAGE, PRIMARILY CONFINED 
SOUTH AND WEST OF THE CENTER DUE TO NORTHEASTERLY WIND SHEAR. WHILE 
THE VORTEX REMAINS VERTICALLY TILTED DUE TO THIS SHEAR, THE LLCC HAS 
BECOME BETTER DEFINED AND MORE SYMMETRIC IN RECENT HOURS. AN 182230Z 
SSMIS MICROWAVE IMAGE REVEALED TIGHTLY COILED LOW-LEVEL CLOUD BANDS 
AROUND THE LLCC. AN EARLIER 181611Z ASCAT PASS SHOWED 25-30 KNOT WIND 
BELTS TO THE NORTH AND SOUTH OF THE LLCC, THOUGH THE MAXIMUM WINDS 
REMAINED SOMEWHAT DISTANT (ABOUT 80 NM) FROM THE CENTER, INDICATING 
THAT AN ORGANIZED INNER CORE WIND FIELD HAS NOT YET DEVELOPED. THE 
ENVIRONMENT IS GENERALLY FAVORABLE FOR DEVELOPMENT WITH WARM SEA 
SURFACE TEMPERATURES (28-29 DEGREES CELSIUS), MODERATE POLEWARD 
OUTFLOW ALOFT, AND A REGION OF DEEP MOISTURE ENCOMPASSING THE LLCC. 
MODERATE VERTICAL WIND SHEAR (15-20 KNOTS) IS THE PRIMARY LIMITING 
FACTOR SHORT-TERM. AS THE SYSTEM BEGINS TO MOVE SOUTHWARD, IT WILL 
ENTER A REGION OF LIGHTER VERTICAL SHEAR OVER THE NEXT 24 HOURS. WITH 
THE WELL-DEFINED LLCC AS A FOUNDATION, THIS IS EXPECTED TO ALLOW THE 
VORTEX TO BECOME MORE VERTICALLY ALIGNED, WITH DEEP CONVECTION 
GRADUALLY SYMMETRIZING AROUND THE LLCC. PHYSICAL AND AI-BASED MODELS 
ALIKE ARE DEVELOPING A STRONG CONSENSUS FOR SHORT-TERM DEVELOPMENT. 
THE ECMWF AND GFS GLOBAL MODELS SHOW THE CYCLONE REACHING WARNING 
THRESHOLD IN 24 TO 36 HOURS, THE HIGH-RESOLUTION HWRF AND HAFS-A 
MODELS IN 12 TO 24 HOURS, AND THE GOOGLE DEEPMIND ENSEMBLE MEAN IN 12 
TO 24 HOURS. THESE MODELS ALSO GENERALLY AGREE ON A SHORT-TERM 
SOUTHWARD TRACK, BENDING SOUTH-SOUTHWESTWARD AND THEN SOUTHWESTWARD 
OVER THE NEXT 48 HOURS. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED 
AT 27 TO 32 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 IS UPGRADED TO HIGH. SEE REF A 
(WTXS21 PGTW 190100) FOR FURTHER DETAILS.
      (2) NO OTHER SUSPECT AREAS.
   C. SUBTROPICAL SYSTEM SUMMARY:
      (1) THE AREA OF CONVECTION (SUBTROPICAL STORM 21S) PREVIOUSLY 
LOCATED NEAR 31.5S 42.1E IS NOW LOCATED NEAR 36.8S 42.3E, 
APPROXIMATELY 876 NM SOUTH OF EUROPA ISLAND. ANIMATED ENHANCED 
INFRARED SATELLITE IMAGERY (EIR) DEPICTS A FULLY EXPOSED LOW-LEVEL 
CIRCULATION (LLCC) WITH FLARING CONVECTION LOSING INTENSITY IN THE 
SOUTHERN QUADRANT. ENVIRONMENTAL ANALYSIS FOR THE AREA INDICATES 
UNFAVORABLE CONDITIONS FOR TRANSITION TO A FULLY TROPICAL SYSTEM WITH 
LOW TO MODERATE VERTICAL WIND SHEAR (15-20 KNOTS), COOL SEA SURFACE 
TEMPERATURES (2122 DEGREES CELSIUS) AND WEAK POLEWARD OUTFLOW ALOFT. 
GLOBAL MODELS ARE IN GOOD AGREEMENT THAT 21S WILL CONTINUE TO WEAKEN 
AS IT MOVES FARTHER SOUTH OVER PROGRESSIVELY COLDER WATERS. FOR 
HAZARDS AND WARNINGS, REFERENCE THE FLEET WEATHER CENTER SAN DIEGO 
HIGH WINDS AND SEAS PRODUCT OR REFER TO LOCAL WMO DESIGNATED FORECAST 
AUTHORITY. MAXIMUM SUSTAINED SURFACE WINDS ARE ESTIMATED AT 37 TO 43 
KNOTS. MINIMUM SEA LEVEL PRESSURE IS ESTIMATED TO BE NEAR 991 MB. THE 
POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN 
THE NEXT 24 HOURS IS LOW.
      (2) NO OTHER SUBTROPICAL SYSTEMS.
3. JUSTIFICATION FOR REISSUE: UPGRADED AREA IN PARA. 2.B.(1) TO 
HIGH.//
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