In most basins in Scandinavia and Finland, more than 50 % of the annual precipitation falls as snow. Errors in snowmelt timing and melt rate simulations are one of the largest sources of stream flow prediction errors in snowmelt-dominated watersheds. Thus snow storage and melting periods have a significant impact on hydropower production reservoirs. Forecasts of reservoir inflow and energy prices are used to schedule the quantity and timing of releases for daily, weekly, and seasonal operations. Ingestion of Earth Observation (EO) based snow observations can significantly reduce hydrological model snowpack simulation uncertainties. The use of EO based snow observations offer two main types of advantages: 1) EO based snow observations are independent from point scale observations (usually used to drive hydrological models), and 2) they provide basin wide information and data on the state of the snowpack as opposed to point scale observations. Tools to assess snow ablation period model and associated forecast uncertainties as well as systems for information dissemination into existing decision support mechanisms requires further development.