May 22 - July 31
Analysis of Color Usage in NWS Flood Graphics
Robert Amstutz, Zoey Rosen, Abby Bitterman, Anna Wanless, and Joseph Ripberger
What is already known:
- Flooding is one of the most common and deadly disasters in the United States
- Color is a prominent aspect of weather graphics that influences public risk perception
What this study adds:
- There is strong overlap in color categories used in flood graphics, with green being predominant
- There is considerable variety in how or what the colors are used for across NWS offices
- Severe storm and flooding risk communication have noteworthy overlap
Abstract:
National Weather Service weather forecasting offices (NWS WFOs) are responsible for graphically communicating hazard information and risk to the public during flooding events. As color is an important part of understanding graphics, color usage is relevant for proper risk communication. This study seeks to identify how color is used by the NWS in graphics for flooding events. In this study, graphics are cataloged for billion-dollar flooding events from WFOs across the United States between 2020 and 2022 up to 5 days prior to and during the flooding event. Both categorical and numerical information were documented for each graphic, and subsequently used in a frequency analysis. Overall, green was the predominant color used in graphics for flooding events, though yellow, orange, and red were also common. There was a wide variety of color ranges used (analogous, monochromatic, or rainbow), as well as key scale types, which describe the type of weather information the office is seeking to communicate (numeric, impact-based, or probability). This implies that while some colors themselves have a strong preferred use, the practical use of color may vary widely between offices. Future research could explore the relationship between different characteristics, such as which colors are most common in displays of weather information.