Snowrad 1996

SNOWRAD was an ETL field experiment performed near Boulder, Colorado from late January to late March 1996. Its purpose is to test a new technique for improving radar estimations of snowfall rates using two wavelengths. Conventional radar snowfall estimations are based on the use of a single wavelength and simple regressions between the radar's reflectivity measurement and independently measured snowfall rates. These are subject to very large errors due to the natural variability of snowflake sizes. The use of an additional shorter wavelength, outside of the Rayleigh scattering regime, provides an independent estimate of the snowflakes' characteristic size which reduces the uncertainties in the problem. ETL operated its NOAA/D and NOAA/K radars in concert to provide dual-wavelength (3.2 cm and 0.87 cm) radar observations of snowstorms and snow showers while measuring the snowfall rates with gages at the ground. These data are being used to test and refine ETL's theoretical studies of the technique.