Streamflow forecasts, updated monthly during the first half of the year, are based on snowpack.
From the National Resources Conservation Service
Soil Moisture Forecasts
Soil moisture anomaly forecast, based on actual conditions and CPC's mid-range forecast
Constructed Analog Forecasts based on Soil Moisture (CAS)
Current 6- to 10-day Outlook (updated Mondays, Wednesdays, and Fridays)
From the Climate Prediction Center