Snowmelt runoff forecasts are being carried out using the SRM mode in several basins of the Spanish Pyrenees.  These results are being used by hydropower companies of Spain for a reasonable management of water resources. We describe a method for snow mapping using NOAA-AVHRR data and a procedure to retrospectively estimate the accumulated snow water equivalent volume with the SRM model. A linear combination of NOAA channels 1 and 2 is used to obtain a snow cover image in which the product is the percent of the snow covered area in each pixel. Real-time snowmelt forecasts are being carried out with the Snowmelt Runoff Model (SRM) using the snow covered area as an input. Even in basins with a total absence of historical discharge and meteorological data, the SRM model provides an estimation of the snowmelt daily discharge. Integrating the forecasted streamflow over the recession streamflow, the snowmelt volume is obtained as a function of time. The function converges asymptotically to the net stored volume of water equivalent of the snowpack.