This map does not represent the layer of snow that will be on the ground in the end. Indeed, it is a map of snowfall precipitation which does not take into account either the melting, the difficulty of the snow to hold or the existing layer. In addition, the AROME / ARPEGE models give the equivalent amount of water in the snowfall, that is to say the number of mm of precipitation fallen and not the true snow layer. An average approximation of a 10: 1 ratio is used here (ie 1 mm of precipitation gives 1 cm of snow) but this ratio is in fact variable: higher if lighter snow, lower if heavier / wet snow.