3.0 EVS Case Study: MARFC
This section describes the use of the Ensemble Verification System (EVS) by the Middle Atlantic River Forecast Center (MARFC) to evaluate ensemble hydrologic forecasts at two points on the Juniata River in Pennsylvania. The data presented in this case study will help us to demonstrate the use of verification to answer important questions about hydrologic forecast performance. Specifically, we will be answering the question, "How are ensemble river forecasts impacted by QPF?"
Several questions come up with respect to the main question. EVS can be used to explore the answers to these questions:
- Does a headwater point show different forecast performance than a downstream point?
- Is the ensemble spread sufficient?
- What are the characteristics of the QPF compared to those of the hydrologic forecasts?
- Is the forecast system skillful?
- What are the characteristics of forecast reliability and forecast discrimination?
- Is there notable difference in the forecast performance when QPF-based ensembles are used compared to climatologically-based QPF?
- What is the impact of lead time on the forecast performance?
- How confident are we with the verification results?