SIO: INVEST 90S

[Nancy Smar]

90S INVEST 200624 0600 8.0S 80.0E SHEM 15 0

[Nancy Smar]

ABIO10 PGTW 250100
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE INDIAN
/OCEAN/REISSUED/250100Z-251800ZJUN2020//
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 90S) PREVIOUSLY LOCATED
NEAR 8.3S 77.0E IS NOW LOCATED NEAR 9.3S 79.6E, APPROXIMATELY 443 NM
EAST OF DIEGO GARCIA. ANIMATED ENHANCED INFRARED SATELLITE IMAGERY
DEPICTS FLARING DEEP CONVECTION WITH FORMATIVE BANDING AROUND A LOW
LEVEL CIRCULATION (LLC). A 242016Z AMSR2 89GHZ MICROWAVE IMAGE
REVEALS SHALLOW BUT WELL ORGANIZED LOW LEVEL STRUCTURE. A 241636Z
ASCAT-C PASS INDICATED THE LLC IS ELONGATED WITH 20-25 KNOT WINDS,
AND IS CONSISTENT WITH THE AMSR2 DATA. INVEST 90S IS CURRENTLY IN A
MARGINAL ENVIRONMENT WITH GOOD WESTWARD OUTFLOW, AND WARM (29 TO 30
CELSIUS) SEA SURFACE TEMPERATURES OFFSET BY HIGH (20-25KT) VERTICAL
WIND SHEAR. GLOBAL MODELS INDICATE THAT INVEST 90S WILL REMAIN QUASI-
STATIONARY WITH LIMITED POTENTIAL FOR WEAK DEVELOPMENT, BEFORE
ACCELERATING WESTWARD AND DISSIPATING. MAXIMUM SUSTAINED SURFACE
WINDS ARE ESTIMATED AT 20 TO 25 KNOTS. MINIMUM SEA LEVEL PRESSURE IS
ESTIMATED TO BE NEAR 1003 MB. DUE TO IMPROVING STRUCTURE AND MODEL
DEVELOPMENT, THE POTENTIAL FOR THE DEVELOPMENT OF A SIGNIFICANT
TROPICAL CYCLONE WITHIN THE NEXT 24 HOURS IS UPGRADED TO MEDIUM.
(2) NO OTHER SUSPECT AREAS.
C. SUBTROPICAL SYSTEM SUMMARY: NONE.
3. JUSTIFICATION FOR REISSUE: UPGRADED AREA IN PARA 2.B.(1) TO
MEDIUM.//
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