One way of predicting snowmelt-driven runoff with imperfect measurements of precipitation is to look at the co-variability between large-scale modes of atmospheric variability, such as the North Atlantic Oscillation (NAO), meteorological fields, and streamflow into reservoirs. In Scandinavia, hydroelectric power is a major source of electricity generation. This region has a largely snowmelt-driven water supply that arrives in winter via a series of synoptic storms. The magnitude and timing of these storms are strongly controlled by the NAO. As it turns out, the NAO index (a measure of the pressure gradient between the mid-latitude and sub-polar atmosphere over the North Atlantic) can predict over half of the variability in Norway's potential water resources. The index can also be used to successfully predict the price for electricity on the regional market.

These results were published here:

Cherry, J., H. Cullen, M. Visbeck, A. Small, and C. Uvo, 2005. “Impacts of the North Atlantic Oscillation on Scandinavian hydropower production and energy markets”. Water Resource Management, 19, 673-691. PDF