Redesigning Hurricane Threats and Impacts Graphics: Effects of Risk Category Levels and Labeling on Non-Expert Multi-Hazard Risk Assessment.

During the past decade, the National Weather Service expanded their graphical forecast product suite to include information about hurricane hazards, via the Hurricane Threats and Impacts (HTI) graphics. The HTI graphics use deterministic and probabilistic forecasts from NOAA to depict potential threatening conditions, accompanied by descriptions of the likely impacts. Although the HTI graphics have been operational since 2015, they are rarely used by the public and subject to misinterpretation. Product redesign offers an opportunity to improve the communication effectiveness of this multi-hazard product. We have employed a user-centered design process, integrating feedback from stakeholders and non-experts, and using visualization design principles to guide the development of a prototype HTI redesign. Our efforts have been stepwise, focusing on specific warning design characteristics, individually, to inform subsequent design iterations.

In this study, we examine existing risk category systems, specifically threat levels and labels, as research has revealed these to be subject to misunderstanding by non-experts. The data are collected via a 2 (Location: Inland, Coastal) × 3 (Risk Category Design: 3-Slight, 3-Moderate, 4-Slight) x 3 (Hurricane: Irma, Michael, Ian) mixed design online experiment. We evaluate the impact of community location, risk category design, hurricane, and individual factors on non-expert comprehension, perceived risk, precautionary intent, and design preferences. In this presentation, we report on the results of the experiment conducted with 360 non-experts living in hurricane-prone areas to elicit their perspectives on the presentation of current and alternative risk categories. The findings from this study will be used to inform redesign efforts of hurricane hazard products in collaboration with NOAA.