The Weather Model Arms Race: Flood Prediction

Two University of Iowa researchers recently tested the ability of the world's most advanced weather forecasting models to predict the Sept. 9-16, 2013 extreme rainfall that caused severe flooding in Boulder, Colo.

The results, published in the December 2013 issue of the journal Geophysical Research Letters, indicated the forecasting models generally performed well, but also left room for improvement.

David Lavers and Gabriele Villarini, researchers at IIHR -- Hydroscience and Engineering, a UI research facility, evaluated rainfall forecasts from eight different global numerical weather prediction (NWP) models.

During September 2013, Boulder County and surrounding areas experienced severe flooding and heavy rain resulting in fatalities, the loss of homes and businesses, and the declaration of a major disaster.

After the storms had subsided, Lavers and Villarini decided to examine how well some of the leading NWP models had done. As a constantly improving science, NWP involves integrating current weather conditions through mathematical models of the atmosphere-ocean system to forecast future weather. For their study, the researchers selected the actual rainfall forecasts made by eight state-of-the-art global NWP models for the period of the Colorado floods.