Hydro Power Forecast
Hydropower forecasting can be useful over a large range of time scales. Reservoir operators need to know how much precipitation is to be expected from large storms in the near term so that they can maintain reservoir levels within safe tolerances. Longer term forecasts, covering several months, can assist maintaining minimum flow levels over long dry seasons.
MDA Weather Services provides two main hydro forecast products:
The Western Utilicast Report provides a daily forecast of temperature and precipitation departure from normal for 1-15 day period in the western United States. During the Northwest water season, its second page gives extra focus to the Pacific Northwest, specifically the Columbia basin. The report also highlights average basin stream flow information as well as snow water equivalent information for parts of the Northwest.
The Water Supply Forecast, issued jointly with Riverside, consists of a once-a-week report containing a meteorological and hydrological discussion of the Pacific Northwest, focusing on the Columbia River flow forecasts at the Dalles and at Grand Coulee Dam. It gives flow volumes for certain monthly and multi-month periods as well as the departure from normal and change since the last forecast.