Welcome to the MISVA website!
MISVA – Monitoring and forecast of IntraSeasonal Variability over Africa – is a joint research / operational collaborative action between Meteo-France and the West African weather forecasting services: ANACIM (Senegal), Mali Meteo, ANAM Burkina Faso , DMN Niger, ANAM Chad and DMN Togo. This action aims at a better understanding and better forecasting of rains, especially extreme rains, in West Africa at synoptic to sub-seasonal scales. To this end, a series of products of numerical forecast models, satellite products and in situ observations are developed at the state of the art by the CNRM and updated daily on this site. These products are discussed weekly during a briefing, every Tuesday (info here) and a daily summary of the most effective products is available by subscribing to the daily summary mailing list (here) or accessible here.
Important: The MISVA site is not operationally maintained. This site is maintained by Meteo-France and the French university service SEDOO-AERIS with funds from the World Meteorological Organization.
The following products are accessible by clicking on the left:
- Bulletins: daily summary (daily_summary), ANASYG (WASA) and summary of weekly briefings
- Observation Products: Based on IMERG satellite products for rain, NOAA for OLR, Reynolds for SST, and ANACIM rain gauges. They are available at daily, weekly, monthly time steps. Hints of onet, hovmollers are available.
- Sub-seasonal forecast: products taken from the ECMWF ensemble forecasts from D0 to D + 45 at resolution 0.75 × 0.75, at daily and weekly time steps.
- Synoptic forecast: products taken from the deterministic model of ECMWF at 0.75 × 0.75, at 6h or daily time step
The methodology and products at the heart of MISVA revolve around a few concepts detailed in the documentation tab. A quick start is presented in the “Getting started with MISVA” tab as well as a free access to the chapters of the Weather Forecater’s Handbook. A more precise documentation in the rest of the menus. Two methodological aspects are used frequently:
- We consider the gross fields and their intra-seasonal anomalies, simply called anomalies here, which are the difference between the gross field and the smoothed climatological annual daily cycle (more details here).
- The work in anomaly makes it possible to isolate the specificity of the day or week considered. We work on the mechanisms of rain variability (East African waves, equatorial waves, thermal depression) from parameters aggregating information. They are the precipitable water (PW), the 925-600 hPa integrated meridional wind (Mean-Vwind), low levels mean products, including vorticity (LowLevel-Diag) and the velocity potential and streamfunction at 200 and 700 hPa.