AWIO20 FMEE 241207
TROPICAL CYCLONE CENTER / RSMC LA REUNION / METEO-FRANCE

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

DATE: 2026/01/24 A 1200 UTC

PART 1: WARNING SUMMARY

NIL.

PART 2 : TROPICAL WEATHER DISCUSSION:

The basin has a monsoon trough (MT) configuration east of 50E between 08 S and 14 S. Convection is weak over the northern part of the MT but locally moderate at the eastern and western ends of the MT and near the Comoros archipelago.

Our basin is currently under the influence of a dry phase of the MJO, which is not conducive to cyclogenesis. However, the arrival of a Kelvin wave over the western part of the basin intersecting with an equatorial Rossby wave could strengthen the northwest flow and make conditions more favorable for cyclogenesis on both sides of Madagascar by the middle of next week.

In connection with the waves overlapping over the western part of the basin, some deterministic models, like GFS, and ensemblist models, suggest the development of a low-pressure system north of the Mascarene Islands by Monday or Tuesday. However, the lack of convergence on the polar side could limit the development of this system at first.

The likelihood of the formation of a moderate tropical storm becomes low from tuesday 27th north of Mascarene Islands.

At the same time, a second low-pressure system,  identified mainly by ensemble models, could form in the central part of the Mozambique Channel early next week. However, its potential for development could also be limited initially due to dry air in the middle troposphere on the polar side of the circulation.

The likelihood of the formation of a moderate tropical storm becomes low from Wednesday 28th in the central part of the Mozambique Channel.



The arrival of a new Rossby wave from the east of the basin could improve convergence in the lower layers and create conditions favorable to cyclogenesis.

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.