A project to demonstrate National Weather Service (NWS) capability to produce probabilistic river stage forecasts is underway in the upper Monagahela river basin in West Virginia and Pennsylvania. NWS forecast offices at Charleston, WV and Pittsburgh, PA are producing probabilistic precipitation forecast information for the next 24 hours. This information is composited at the Ohio Basin River Forecast Center (OHRFC) and used as input to the EPP to produce an ensemble of time series of gridded fields of 6-hour future precipitiation. This gridded ensemble is transformed into an ensemble of basin average precipitation time series that are input to a hydrologic forecast model for the basin. Alternative EPP techniques have been developed and are now being tested. The results so far will be reviewed