The vertically pointing S-band radar precipitation profiler (S-PROF) was designed and built by Earth System Research Laboratory (ESRL) engineers in the late 1990's to probe precipitation in the coastal mountains of Sonoma County for a research project called CALJET, a precursor to HMT. The S-PROF provides highly resolved (60-m vertically, 1 min. temporally) profiles of radar reflectivity and Doppler vertical velocity that can be used to identify and characterize NBB rain. The CALJET S-PROF deployment proved to be useful from both research and NWS operations perspectives, and four additional S-PROFs were built and deployed in subsequent field campaigns. More recently, ESRL engineers designed, built, and tested a much less expensive frequency modulated, continuous wave (FM-CW) S-band radar for a project with the California Department of Water Resources (CA-DWR). These radars provide similar information to the S-PROF and also are very useful for automated detection of the snow level (defined here as the altitude of peak radar reflectivity in the bright band) during precipitation. Ten of these new snow-level radars are being deployed at major watersheds across California for CA-DWR, and the snow level observations are being sent to NWS Western Region offices in the prescribed format for inclusion in the office's hydrologic database. The snow level is critical to runoff in mountainous watersheds because it determines the areal extent of the watershed that will be exposed to rain versus snow. ESRL's snow level product (derived from S-PROFs, snow-level radars, and Doppler wind profilers) has been used extensively by forecasters at the California/Nevada River Forecast Center, who otherwise struggle with verifying their snow level forecasts that are based mostly on numerical weather prediction guidance.