(1) THE AREA OF CONVECTION (INVEST 93S) PREVIOUSLY LOCATED
NEAR 14.2S 79.6E HAS DISSIPATED AND IS NO LONGER SUSPECT FOR THE
DEVELOPMENT OF A SIGNIFICANT TROPICAL CYCLONE IN THE NEXT 24 HOURS.
ABIO10 PGTW 310930
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE INDIAN OCEAN
/REISSUED/310930Z-311800ZOCT2021//
REF/A/MSG/JOINT TYPHOON WRNCEN PEARL HARBOR HI/302051ZOCT2021
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 93S) PREVIOUSLY LOCATED
NEAR 12.1S 82.6E IS NOW LOCATED NEAR 13.1S 80.2E, APPROXIMATELY 576
NM SOUTHEAST OF DIEGO GARCIA. ANIMATED ENHANCED INFRARED (EIR)
SATELLITE IMAGERY AND A 310802Z AMSR2 89GHZ IMAGE REVEAL A BROAD LOW
LEVEL CIRCULATION CENTER (LLCC) DEFINED BY WELL-DEFINED, BUT SHALLOW
BANDING WITH VERY WEAK CONVECTION SHEARED TO THE SOUTHWEST.
ENVIRONMENTAL ANALYSIS INDICATES AN UNFAVORABLE ENVIRONMENT FOR
DEVELOPMENT WITH HIGH (25-30 KNOTS) NORTHEAST VERTICAL WIND SHEAR
AND MARGINAL SEA SURFACE TEMPERATURES (26C) OFFSET BY GOOD POLEWARD
OUTFLOW. ADDITIONALLY, THERE IS SIGNIFICANT DRY AIR ENTRAINMENT
THROUGHOUT THE MID-LEVELS THAT IS HINDERING CONVECTIVE DEVELOPMENT.
GLOBAL MODELS ARE IN GOOD AGREEMENT THAT THE CIRCULATION ASSOCIATED
WITH INVEST 93S WILL CONTINUE TO TRACK WESTWARD, BUT IT IS NOT
EXPECTED TO DEVELOP AT THIS TIME. MAXIMUM SUSTAINED SURFACE WINDS
ARE ESTIMATED AT 20 TO 25 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 IS DOWNGRADED
TO LOW. THIS CANCELS REF A.
(2) NO OTHER SUSPECT AREAS.
C. SUBTROPICAL SYSTEM SUMMARY: NONE.
3. JUSTIFICATION FOR REISSUE: CANCELLED TCFA FOR AREA IN PARA 2.B.(1)
(INVEST 93S).//
NNNN
WTXS21 PGTW 292100 COR
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/TROPICAL CYCLONE FORMATION ALERT (INVEST 93S) CORRECTED//
RMKS/
1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
120 NM EITHER SIDE OF A LINE FROM 9.8S 86.7E TO 12.8S 80.9E
WITHIN THE NEXT 12 TO 24 HOURS. AVAILABLE DATA DOES NOT JUSTIFY
ISSUANCE OF NUMBERED TROPICAL CYCLONE WARNINGS AT THIS TIME.
WINDS IN THE AREA ARE ESTIMATED TO BE 20 TO 25 KNOTS. METSAT
IMAGERY AT 291810Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 10.0S 86.6E. THE SYSTEM IS MOVING SOUTH-SOUTHWESTWARD AT 11
KNOTS.
2. REMARKS:
THE AREA OF CONVECTION (INVEST 93S) PREVIOUSLY LOCATED NEAR 9.6S
86.9E IS NOW LOCATED NEAR 10.0S 86.6E, APPROXIMATELY 851 NM EAST OF
DIEGO GARCIA. ANIMATED ENHANCED INFRARED (EIR) SATELLITE IMAGERY AND
A 291307Z SSMIS 91GHZ IMAGE REVEALS AN AREA OF DEEP CONVECTION
LOCATED SOUTHWEST OF AN ASSESSED LOW LEVEL CIRCULATION (LLC). A
PARTIAL 291604Z ASCAT METOP-B PASS SHOWS THE EAST SIDE OF THE
AFOREMENTIONED LLC WITH 20-25 KT WINDS LOCATED IN THE SOUTHERN
SEMICIRCLE. ENVIRONMENTAL ANALYSIS INDICATES INVEST 93S IS IN A
MARGINALLY FAVORABLE ENVIRONMENT WITH GOOD WESTWARD AND POLEWARD
OUTFLOW SUPPORTED BY ANTICYCLONIC TURNING ALOFT AND WARM (28-29C)
SEA SURFACE TEMPERATURES, OFFSET BY MODERATE (15-20KT) VERTICAL WIND
SHEAR. GLOBAL MODELS ARE IN AGREEMENT THAT INVEST 93S WILL TRACK
WESTWARD AND CONSOLIDATE OVER THE NEXT 24 HOURS. MAXIMUM SUSTAINED
SURFACE WINDS ARE ESTIMATED AT 20 TO 25 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 IS HIGH.
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY
302100Z.
4. JUSTIFICATION FOR CORRECTION: CORRECTED PREVIOUS POSITION IN
PARA. 2.//
NNNN
ABIO10 PGTW 291800
MSGID/GENADMIN/JOINT TYPHOON WRNCEN PEARL HARBOR HI//
SUBJ/SIGNIFICANT TROPICAL WEATHER ADVISORY FOR THE INDIAN
OCEAN/291800Z-301800ZOCT2021//
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 93S) PREVIOUSLY LOCATED
NEAR 6.6S 86.6E IS NOW LOCATED NEAR 9.6S 86.9E, APPROXIMATELY 866 NM
EAST OF DIEGO GARCIA. ANIMATED ENHANCED INFRARED (EIR) SATELLITE
IMAGERY AND A 291307Z SSMIS 91GHZ IMAGE REVEAL AN AREA OF DEEP
CONVECTION LOCATED SOUTHWEST OF AN ASSESSED LOW LEVEL CIRCULATION
(LLC). A PARTIAL 291604Z ASCAT METOP-B PASS SHOWS THE EAST SIDE OF
THE AFOREMENTIONED LLC WITH 20-25 KT WINDS LOCATED IN THE SOUTHERN
SEMICIRCLE. ENVIRONMENTAL ANALYSIS INDICATES INVEST 93S IS IN A
MARGINALLY FAVORABLE ENVIRONMENT WITH GOOD WESTWARD AND POLEWARD
OUTFLOW SUPPORTED BY ANTICYCLONIC TURNING ALOFT AND WARM (28-29C)
SEA SURFACE TEMPERATURES, OFFSET BY MODERATE (15-20KT) VERTICAL WIND
SHEAR. GLOBAL MODELS ARE IN AGREEMENT THAT INVEST 93S WILL TRACK
WESTWARD AND CONSOLIDATE OVER THE NEXT 24 HOURS. MAXIMUM SUSTAINED
SURFACE WINDS ARE ESTIMATED AT 20 TO 25 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.//
NNNN