The Experimental Winter Precipitation Forecast provides a forecast of winter precipitation (December-March) for the western United States and is determined using both Pacific and Atlantic Ocean temperatures. Forecasts are available November - February and use the most recent 2-3 months of observed Pacific Ocean temperatures (El Niño Southern Oscillation or ENSO temperature index) and observed Atlantic Ocean temperatures (Atlantic Quadpole Mode or AQM temperature index). The Experimental Winter Precipitation Forecast Tool and the underlying research was developed by scientists at the University of Utah in close collaboration with Salt Lake City Department of Public Utilities and Western Water Assessment.