Abstract
Although severe weather forecast products, such as the Storm Prediction Center (SPC) convective outlook, are much more accurate than climatology at day-to-week time scales, tornadoes and severe thunderstorms claim dozens of lives and cause billions of dollars in damage every year. While the accuracy of this outlook has been well documented, less work has been done to explore the comprehension of the product by nonexpert users like the general public. This study seeks to fill this key knowledge gap by collecting data from a representative survey of U.S. adults in the lower 48 states about their use and interpretation of the SPC convective outlook. Participants in this study were asked to rank the words and colors used in the outlook from least to greatest risk, and their answers were compared through visualizations and statistical tests across multiple demographics. Results show that the U.S. public ranks the outlook colors similarly to their ordering in the outlook but switches the positions of several of the outlook words as compared to the operational product. Logistic regression models also reveal that more numerate individuals more correctly rank the SPC outlook words and colors. These findings suggest that the words used in the convective outlook may confuse nonexpert users, and that future work should continue to use input from public surveys to test potential improvements in the choice of outlook words. Using more easily understood words may help to increase the outlook’s decision support value and potentially reduce the harm caused by severe weather events.
Significance Statement
The Storm Prediction Center’s Convective Outlook, though originally designed for expert users, has become popular as a communication tool for the general public through broadcast and social media. We wanted to identify a baseline for how well people understand the words and colors used in the outlook to communicate risk, using a series of survey questions issued to U.S. adults. Our results suggest that the outlook words do not clearly communicate risk to public users, and that future iterations of the outlook should use terms that are easily sequentially ordered. Future work should seek to identify terms that are more easily understood by experts and nonexperts alike.
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