Soil moisture is an important component in determining watershed hydrologic condition, and as a contributor to stream flow. Most hydrologic models use precipitation and soil climate information as surrogates for soil water-holding capacity, antecedent soil moisture and water flow through  soil. The Natural Resources Conservation Service (NRCS)  installed soil moisture and soil temperature sensors in their Soil Climate Analysis Network (SCAN) and in some SNOwpack TELemetry (SNOTEL) stations throughout the U.S. The moisture and temperature data, at each location, is collected hourly at 4 to 5 soil depths. Some sites have  more than 10 years of data. Soil moisture data, in conjunction with other parameters, is statistically analyzed for water supply forecasting. A soil moisture index has been developed from this measured data, which calculates soil moisture for a pedon using specific detailed soil and site characteristics. This index provides the antecedent moisture content and storage of the soil which is being tested as a way to improve water supply forecasting for a watershed.