Snow wetness measurements and runoff forecasting

This paper presents results of our research in recent years, directed toward the development of snow-wetness measuring systems. During the 1979-80 season, microwave attenuation data were abtained twice daily for horns within the snowpack, from which the snow wetness was calculated using calibration equations. These tests were made at the Central Sierra Snow Laboratory; concurrent data were obtained on snow water equivalent and other meteorological quantities.The beginning of the pack-snowmelt was clearly evident in the microwave data; its timing agrees well with the changes in snow water equivalent. The increase in wetness during a day, and the decrease in wetness produced by drainage overnight were also readily measured. Results are given for water retention capability of the snow in volume and in weight percent.A brief discussion is given of the application of snow wetness data to runoff forecasting.