ABIO10 PGTW 291800
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE INDIAN 
OCEAN/291800Z-301800ZDEC2020//
REF/A/MSG/JOINT TYPHOON WRNCEN PEARL HARBOR HI/290751ZDEC2020//
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: NONE.
   C. SUBTROPICAL SYSTEM SUMMARY: NONE.    
2. SOUTH INDIAN OCEAN AREA (135E WEST TO COAST OF AFRICA):
   A. TROPICAL CYCLONE SUMMARY:
      (1) AT 29DEC20 0600Z, TROPICAL CYCLONE 07S (CHALANE) WAS LOCATED 
NEAR 19.6S 39.9E, APPROXIMATELY 157 NM NORTH OF EUROPA ISLAND, AND HAD 
TRACKED WESTWARD AT 16 KNOTS OVER THE PAST SIX HOURS. MAXIMUM 
SUSTAINED SURFACE WINDS WERE ESTIMATED AT 45 KNOTS GUSTING TO 55 
KNOTS. SEE REF A (WTXS31 PGTW 290900) FOR FURTHER DETAILS.
      (2) NO OTHER TROPICAL CYCLONES.
   B. TROPICAL DISTURBANCE SUMMARY:
      (1) THE AREA OF CONVECTION (INVEST 93S) PREVIOUSLY LOCATED NEAR 
10.4S 90.0E IS NOW LOCATED NEAR 11.9S 86.5E, APPROXIMATELY 611 NM WEST 
OF COCOS ISLANDS. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY AND A 
291551Z METOP-B 89GHZ SATELLITE IMAGE DEPICT DISORGANIZED BANDING 
WRAPPING INTO A LOW LEVEL CIRCULATION CENTER (LLCC) WITH FLARING 
CONVECTION IN THE WESTERN SEMI-CIRCLE. A 290204Z ASCAT-A IMAGE SHOWS A 
WELL DEFINED CIRCULATION WITH MOSTLY 10 KNOT WINDS WITH 15-20 KNOT 
WINDS IN THE SOUTHERN SEMICIRCLE. INVEST 93S IS IN A FAVORABLE 
ENVIRONMENT FOR DEVELOPMENT WITH POLEWARD OUTFLOW ALOFT, MODERATE (15-
20 KTS) VERTICAL WIND SHEAR AND WARM (28-29C) SEA SURFACE 
TEMPERATURES. GLOBAL MODELS ARE IN GENERAL AGREEMENT THAT INVEST 93S 
WILL TRACK SOUTHWESTWARD AND INTENSIFY OVER THE NEXT 24 HOURS. MAXIMUM 
SUSTAINED SURFACE WINDS ARE ESTIMATED AT 15 TO 20 KNOTS. MINIMUM SEA 
LEVEL PRESSURE IS ESTIMATED TO BE NEAR 1007 MB. THE POTENTIAL FOR THE 
DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS 
IS UPGRADED TO MEDIUM.
      (2) AN AREA OF CONVECTION (INVEST 96S) HAS PERSISTED NEAR 10.4S 
70.5E, APPROXIMATELY 214 NM SOUTH-SOUTHWEST OF DIEGO GARCIA. ANIMATED 
ENHANCED INFRARED SATELLITE IMAGERY AND A 291336Z SSMIS 91GHZ 
SATELLITE IMAGE DEPICT DISORGANIZED BANDING WRAPPING INTO A POORLY 
DEFINED LOW LEVEL CIRCULATION CENTER (LLCC) WITH FLARING CONVECTION IN 
THE WESTERN AND NORTHERN SEMI-CIRCLES. INVEST 96S IS IN A MODERATELY 
FAVORABLE ENVIRONMENT FOR DEVELOPMENT WITH WESTWARD AND POLEWARD 
OUTFLOW ALOFT, STRONG TO MODERATE (20-25 KTS) VERTICAL WIND SHEAR AND 
WARM (28-29C) SEA SURFACE TEMPERATURES. GLOBAL MODELS ARE IN GENERAL 
AGREEMENT THAT INVEST 96S WILL SLOWLY TRACK SOUTHEASTWARD WITH LITTLE 
INTENSIFICATION OVER THE NEXT 24 HOURS. MAXIMUM SUSTAINED SURFACE 
WINDS ARE ESTIMATED AT 15 TO 20 KNOTS. MINIMUM SEA LEVEL PRESSURE IS 
ESTIMATED TO BE NEAR 1007 MB. THE POTENTIAL FOR THE DEVELOPMENT OF A 
SIGNIFICANT TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS UPGRADED TO 
LOW.
       (3) NO OTHER SUSPECT AREAS.
   C. SUBTROPICAL SYSTEM SUMMARY: NONE.//
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