AWIO20 FMEE 121106
TROPICAL CYCLONE CENTER / RSMC LA REUNION / METEO-FRANCE

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

DATE: 2026/04/12 A 1200 UTC

PART 1: WARNING SUMMARY

NIL.

PART 2 : TROPICAL WEATHER DISCUSSION:

The basin exhibit a Near-Equatorial Trough (NET) pattern, east of 50oE and between 4oS and 8oS. Convective activity is weak on the northern side of the NET along the equator and east of Tanzania. A convective area is also developing at the outer edge of the NET near the Cocos Islands.

The low-frequency context is currently unfavorable for cyclogenesis, with an easterly wind anomaly along the equator. However, the westerly wind anomaly in the wake of the MJO allows a NET structure to persist over the central and eastern parts of the basin. In the coming days, a dry MJO context is expected, further reducing the likelihood of cyclogenesis. Only the passage of an equatorial Rossby wave through the eastern part of the basin could trigger cyclogenesis in the aforementioned TPE, but it may remain within the Australian basin.







10-day outlook:
The development of an equatorial Rosby wave could enhance the vorticity within the NET east of 90oE by mid-April. There is therefore a low probability that a low-pressure system will form east of 90oE and move into our area of responsibility at the end of next week.

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.