Precipitation and snow level are both time series. They are set simultaneously in the same dialog. This dialog is gotten by selecting Precipitation from the system menu:

This gets the following dialog:

As shown in the dialog, precipitation is in inches per time step over the basin. The snow level is used to determine whether precipitation falls as rain or as snow. For elevation bands below the snow level, precipitation falls as rain.

Note that this same dialog may be gotten for each individual basin. In that case, the precipitation and snow level apply only to the basin selected. In the case where the dialog is gotten from the top level menu, it applies to all basins in the model.