Comparison of sequential and variational assimilation methods to improve hydrological predictions in snow dominated mountainous catchments

•Assimilation of streamflow and snow data using variational and sequential techniques in a hydrological model.•Satellite snow coverage products are assimilated together with streamflow data.•Variational techniques outperform sequential techniques in two mountainous basins.•Average relative gains in variational assimilation are 49% for streamflow and 28% for snow data.