The National Water Model (NWM) is a new product from the National Weather Service that forecasts streamflow over the entire continental United States. It is a hydrologic model that predicts the flow in every river reach of the National Hydrography Dataset, mathematically modeling physical processes like snowmelt, infiltration and the movement of water through soil layers in order to determine how much of the NWS precipitation forecast becomes runoff, then routing that runoff through the river network. This is the medium term forecast, which is run once a day, predicting streamflow over the next ten days at three hour intervals. Rivers are symbolized according to how the streamflow differs from the monthly normal.What Can You Do With This Layer?This map service is designed for fast data visualization. Identify features by clicking on the map to reveal the pre-configured pop-ups. View the time-enabled data using the time slider, which is set to three hour intervals by default, by Enabling Time Animation. This layer type is not recommended for use in analysis.