Communicating Probabilities for the Better Understanding of Flood Risk

Spring snowmelt flooding along the Red River Valley of the North and its tributaries has significantly impacted infrastructure and daily life, especially over the last two decades. Major category flooding has occurred in 45% of years at some location along the mainstem of the river since the catastrophic "Flood of 1997". Flood outlooks leading up to spring snowmelt flooding are created at the National Weather Service (NWS) North Central River Forecast Center in Chanhassen, MN and are provided in a probabilistic format. The NWS Grand Forks office then communicates the spring flood outlook information with partners along the Red River and its tributaries.

It has been demonstrated in previous research that probabilistic (uncertainty) information leads to more optimal decisions by decision makers (Joslyn and LeClerc, 2011 and Ramos et al., 2013). However, research in the area of probabilistic flood forecasts also indicates that a collaborative effort between the developer and end user helps create a product that will be most useful for the intended recipient (Hogan Carr et al., 2016, Morss et al., 2015 and Demeritt et al., 2010).

A process to improve the presentation of probabilistic flood outlook information for the Red River of the North was initiated at the NWS Grand Forks office in the fall of 2017. This presentation highlights the iterative process of engaging partners and incorporating their input to create an improved set of probabilistic flood outlook graphics for the 2018 spring flood season. It is theorized that improvements to the communication of probabilistic flood information will lead to an increased understanding of flood risk and result in improved preparedness.