While the Total Precipitable Water (TPW) represents the amount of moisture available in an entire atmospheric column, Broadcasters expressed interest in a representation of Precipitable Water (PWAT) in the lowest portion of the atmosphere. Specifically, this product will help define one of the finer details needed in forecasting lake effect snow around the Great Lakes. By creating a map that specifies how much of the TPW is in the lower 5000m, area forecasters can determine what is actually available for lake effect snowfall event.

The Low-Level Precipitable Water will be available every 6 hours as an 18-hour forecast, with 3-hour time steps over a 13-kilometer resolution grid.