Do Advisories, Warnings, or Color Coding Matter to Risk Perception and Precautionary Decisions?

Abstract

Abstract There are lingering questions about the effectiveness of the watch, warning, and advisory system (WWA) used to convey weather threats in the United States. Recently there has been a shift toward alternative communication strategies such as the impact-based forecast. The study reported here compared users’ interpretation of a color-coded impact-based prototype designed for email briefings, to a legacy WWA format. Participants, including emergency managers and members of the public, saw a weather briefing and rated event likelihood, severity, damage, and population affected. Then they recommended emergency response actions. Each briefing described the severity of the weather event and the degree of impact on population and property. In one condition a color-coded impacts scale was added to the text description. In another, an advisory and/or warning was added to the text description. These were compared with the text-only control. Both emergency managers and members of the public provided higher ratings for event likelihood, severity, damage, and population affected and recommended a greater response for higher impact levels regardless of format. For both groups, the color-coded format decreased ratings for lower-impact events. Among members of the public, the color-coded format also led to increases for many ratings and greater response at higher levels relative to the other two conditions. However, the highest ratings among members of the public were in the WWA condition. Somewhat surprisingly, the only effect of the WWA format on emergency managers was to reduce action recommendations, probably because of the inclusion of the “advisory” in some briefings.