About

The southwestern Indian Ocean (SWIO) basin is affected by approximately ten tropical cyclones (TCs) each year during the Southern Hemisphere summer. These extreme convective systems are characterized by violent winds, torrential rainfall, and flooding, posing a major threat to coastal populations. The human and material stakes associated with forecasting such events are therefore extremely high. Improving the representation of cyclone intensity and structure in numerical weather prediction (NWP) models remains a major challenge for forecasters at the Regional Specialized Meteorological Center (RSMC)- Reunion, with the ultimate goal of enhancing the quality of TCs forecasts.

The primary objective of the AVOCAT project is to develop a new Ocean-Wave-Atmosphere (OWA) coupled configuration for the SWIO basin in order to improve TCs forecasting (track, intensity, size, etc.), while ensuring that forecasts of sensitive weather phenomena over La Réunion Island are improved, or at least not degraded.

To achieve this objective, several model configurations will be implemented within Meteo-France’s Operational Launch and Visualization Environment (OLIVE). These configurations will explore different modeling choices, including the use of one-dimensional versus three-dimensional ocean models, the inclusion or exclusion of a wave model, and modifications to air-sea interface parameterization schemes. The configurations will be evaluated over a large sample of TCs in order to identify the most effective setup for simulating key cyclonic parameters. The selected configuration, referred to as the "AVOCAT configuration", will then be tested under operational conditions using 72-hour forecasts.

This project is funded by the European Union under the FEDER-FSE Reunion Program, managed by the Reunion Regional Authority. Through FEDER funding, Europe is actively supporting development and innovation in Reunion.