Here Comes the Rain: A New Approach to Communicating Urban Rain Rates to Support Decision-Making

Decades of social science research have examined the challenge of communicating complex forecast information to different user groups, considering variables from product type and design to target audiences and dissemination methods. While there are a range of usability challenges, including related to the information itself and its presentation, design and accessibility, a common issue remains that there is an abundance of data that needs to be organized and distilled in ways that make it interpretable to the intended audiences. Systems need to ensure that the information provided is what is useful for decision-making by stakeholders - a challenge made harder when end users have a wide spectrum of knowledge and varying ways they access information. Careful consideration of these challenges and creating new approaches to organizing, sharing, and displaying data can support decision-making and action by audiences at risk for severe weather events, including flooding.

The Weather Prediction Center (WPC) of the National Weather Service (NWS) advances development of new and improved hydrometeorological forecast products, and in particular, the delivery of precipitation products. Recently, in efforts to improve extreme precipitation forecasting, the WPC conceptualized a new way of organizing and displaying precipitation data in urban settings with an Urban Rain Rate Dashboard (URRD), which provides real-time probabilities of exceeding average recurrence intervals of rainfall for various US major metropolitan areas. Previous work to categorize critical rainfall thresholds, such as through efforts like Atlas 14, do not adequately explain urban landscape rainfall thresholds. The URRD concept came from previous feedback gathered by WPC about the need for local scale precipitation information that could be used in stormwater management by planners, public works, and municipal audiences. The URRD may help by providing users the likelihood that their city-specific critical rain rate threshold will be exceeded and show the forecast probability of hourly rainfall rates exceeding stormwater design criteria.

While the URRD concept is valued, more testing to understand user needs and capacities to incorporate such data into decision-making, along with how best to design and deliver the information, is necessary. A mixed-method social science research study, led by the Nurture Nature Center, held six focus groups with professional stakeholders in major cities across the United States using URRD prototypes modeled for past extreme weather and flooding events. Focus groups were held virtually with a facilitated discussion around the flooding scenario and included pre and post session surveys to explore user information needs, as well as what design and delivery elements maximize the utility of the dashboard in decision-making for users. The results from this social science research informed recommendations provided to WPC as the URRD prototype is further developed. This presentation details the impetus and approach for the research and describes the findings in addition to lessons learned about design conceptualization for sharing complex data through an accessible and organized dashboard.