AWIO20 FMEE 171145
TROPICAL CYCLONE CENTER / RSMC LA REUNION / METEO-FRANCE

BULLETIN FOR CYCLONIC ACTIVITY AND SIGNIFICANT TROPICAL WEATHER
IN THE SOUTHWEST INDIAN OCEAN

DATE: 2026/09/17 A 1200 UTC

PART 1: WARNING SUMMARY

NIL.

PART 2 : TROPICAL WEATHER DISCUSSION:

The basin is in a winter pattern. Convective activity is weak north of 7oS near Seychelles and Chagos archipelago

The departure of the Kelvin wave that crossed the basin over the past few days puts an end to the temporary near-equatorial trough pattern over the eastern part of the basin and signals a return to a winter pattern. El Nino-driven easterly wind anomalies keep prevailing and maintain a durably unfavorable large-scale pattern for cyclogenesis.

Development of a tropical storm is not expected during the next 5 days.

10-day outlook:
Nothing to report.

NOTA BENE: The likelihood is an estimate of the chance of genesis of a moderate tropical storm over the basin within the next five days:

Very low: less than 10%      Moderate: 30% to 60%      Very high: over 90%
Low: 10% to 30%              High: 60% to 90%

The Southwestern Indian ocean basin extends from the Equator to 40S and from the african coastlines to 90E.