AWIO20 FMEE 151045
TROPICAL CYCLONE CENTER / RSMC LA REUNION / METEO-FRANCE

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

DATE: 2026/10/15 A 1200 UTC

PART 1: WARNING SUMMARY

NIL.

PART 2 : TROPICAL WEATHER DISCUSSION:

The basin exhibits a poorly defined Near-Equatorial Trough pattern west of 65E, just south of the equator. A convective cluster is forming east of the Seychelles near 65oS. No closed clockwise low level circulation is currently present.

Equatorial easterly wind anomalies driven by El Nino and the building positive phase of the Indian Ocean Dipole (IOD) maintain an unfavorable large-scale pattern for cyclogenesis. However, a wet phase of the MJO over the western part of the basin will contribute to enhancing convective activity near the equator. Additionally, the crossing of a Kelvin and Rossby waves favors a westerly burst along the equator.

Near the Seychelles:By next weekend, a closed circulation could form within the NET near the Seychelles archipelago. However, conditions do not appear particularly favorable for its development due to weak to moderate easterly to northeasterly wind shear and a weak equatorial feed.Legacy ensemble models (GEFS, EPS, etc.) have been indicating a low but persistent risk in recent updates. Ensemble AI models are still showing only a marginal signal of cyclogenesis.

In the next 5 days, there is a low chance that a moderate tropical storm will form starting Monday, October 19, near the Seychelles.



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.