Temporal discounting of tornado shelter-seeking intentions amidst standard and impact-based weather alerts: A crowdsourced experiment.

Tornadoes are atmospheric events capable of massive devastation, involving physical destruction and human casualties. Following the 2011 Joplin, MO tornado that claimed the lives of nearly 160 people, the National Weather Service and National Institute of Standards and Technology concluded that better warning systems would have saved lives. This conclusion prompted the creation of impact-based warning (IBW) messages that use explicit language to convey damage threats and potential outcomes. The current study examined the efficacy of impact-based warnings for evoking shelter-seeking intentions in a simulated tornado event. We stratified participants recruited through a crowdsourcing service into 1 of 4 simulated tornado warning conditions, varying with respect to the content and description (IBW) provided. Participants rated their likelihood of immediate shelter-seeking given increasing lead times to the potential tornado strike. Analyses indicated that participants receiving IBW maintained shelter-seeking most across increasing delays. Results suggest viable warning delivery at longer lead times when employing IBW, thereby providing more preparation while bypassing risks of delay-induced inaction.