Estimating and Communicating Hydrologic Ensembles in the Mid Atlantic (323)

Robert Shedd, NOAA/NWS/Middle Atlantic River Forecast Center, State College, PA

Rachel Hogan Carr, Nurture Nature Center

Burrell Montz Covey, East Carolina University



The Middle Atlantic River Forecast Center (MARFC) has begun widespread implementation of the national Hydrologic Ensemble Forecast Service (HEFS) across the Mid-Atlantic US. HEFS is a software suite to provide ensemble river forecasts with forecast durations from a few days out to weeks, months, and even a year into the future. Initial implementations of HEFS utilize the GEFS (Global Ensemble Forecast System) and the CFSv2 (Climate Forecast System) for precipitation and temperature forcings and use various procedures to minimize bias to forcings errors as well as hydrologic model errors.This presentation will discuss two aspects of MARFC's implementation of HEFS. The first piece will address what HEFS is and how it is being implemented specifically in the Mid-Atlantic. We will look at some case studies and hindcast validation results that have been performed prior to implementation. We will also address some of the implementation challenges specifically associated with reservoir modeling with long term ensembles.The second phase of the presentation will present a social science study that has been led by Nurture Nature Center and East Carolina University. This study looked at how we can be improving some of the HEFS product suite in order to make the probabilistic information contained in the products more understandable to a broad variety of users, including the public, emergency managers, and water resources managers.