Food security in West Africa is considered as one of the major development challenges of the region. Food security issues are particularly prevalent there due to strong demographic growth, household food and subsistence based mainly on rain-fed agriculture and high rainfall variability. Added to these factors are the security and health risks facing the region, making agricultural production systems particularly fragile and fluctuating. Thus, the cyclical aspects of agricultural production are combined with those structural aspects of the vulnerability of populations. Since the major droughts of the early 1970s, several crop monitoring and food security early warning systems (EWS) have been developed in the region to enable decision-makers to anticipate crises, and to help plan emergency measures emergency by targeting populations and / or areas at risk. Since 2016, the GEOGLAM Crop Monitor for Early Warning (CM4EW) conducts a deliberative evidence-building process to reach an agreement on monthly crop conditions produced by the different EWS (Becker-Reshef et al., 2020). In these systems, satellite information is mainly used to derive vegetation index anomalies from time series of low spatial resolution images (MODIS or PROBA-V type), and precipitation data. Vegetation anomalies maps are produced from the NDVI value obtained for the current decade and compared to the average NDVI value for the same decade calculated over a reference period or what is assumed to be a normal situation. If satellite images remain the main source of information for EWS at national and regional scales, their use still raises a number of issues: (i) the observed discrepancy between vegetation anomalies produced by different crop monitoring systems (Lemettais L., 2021), while the basic satellite data are identical, and (ii) the detection of a vegetation anomaly in real time is not sufficient to establish a diagnosis on the agricultural production of a region because many factors come in c