The IMS snow cover product combines ground observations and satellite data from microwave and visible sensors (using geostationary and polar orbiting satellites) to provide snow cover information in all weather conditions. The IMS product is available daily for the northern hemisphere. It has been monitored operationally at ECMWF since November 2013. IMS provides a binary information on snow cover (snow or no snow). The model first guess snow cover is compared to that of IMS using a contingency table. Monitoring statistics are expressed using the four elements of the contingency table: Miss rate, Hit rate, false alarm rate and correct-nulls.