Predicting time of peak snowmelt runoff from snow pillow data

The first snow pillow was installed in Montana in 1963. Since then nearly 70 remote snow sensors have been installed and automated. These snow sensors accurately assess the effect of warming spring temperatures by measuring the daily snow water equivalent of the mountain snowpack. Simple time-sequence relationships between snowmelt and day of peak streamflow add another dimension to the hydrologist's ability to predict significant hydrologic events. To determine a relationship requires a few years of snow pillow records and streamgage data. To project dates of peak streamflow requires frequent measurements of snowmelt progress, usually from a real-time data collection system such as SNOTEL. This method provides a simple, realistic estimate of peak flow dates on streams where daily runoff forecast models have not yet been developed, where existing models cannot accurately predict date of peak flow, or as a check for peak flow dates projected with existing models.