Communicating Increased Risk: An Empirical Investigation of the National Weather Service’s Impact-Based Warnings

Abstract

In 2014, following a Central Region pilot assessment, the National Weather Service implemented large-scale use of an experimental product of enhanced severe weather warnings known as impact-based warnings (IBWs). The overarching goal of these IBWs is to improve the threat warning process and motivate appropriate responses by using event tags and additional text that provides more specificity about the magnitude of the storm and its potential consequences. These IBWs are designed to be used by individuals in the field to make more effective decisions. Although qualitative research has shown overall satisfaction with IBWs (Harrison et al. 2014; Losego et al. 2013), little published experimental research has been conducted on these new enhanced warnings. The research reported here therefore empirically investigates the effectiveness of the new IBW experimental product. In three experiments, participants adopted the role of a plant manager and read both IBWs and non-IBWs. At three different decision points, participants made decisions about shutting down the plant and having employees shelter in place. The results of all three experiments show that the IBWs produced higher likelihoods of closing the plant and sheltering in place, but only after the additional IBW text (providing information about the hazard, source, and impact) was presented. Interestingly, participant background knowledge of tornadoes and severe weather had little impact on their shelter in place decisions. The results support the conclusion that the additional enhanced text in IBWs promotes a higher stated likelihood of sheltering in place, at least as measured by behavioral intentions.

Exploring protective decision‐making in the context of impact‐based flood warnings

“…Interestingly, previous experience with flood warnings was found to have little impact on the subject's decision of taking protective action. Casteel (2016) and Weyrich et al (2018) present similar results for IBWs, where background knowledge and experience were also not found to influence the participant's decision to take a protective decision. Users might, therefore, be exposed to such warnings once or twice in their lifetime (Parker et al, 2009); thus, due to the rarity of these events, even if a person has had previous experience with flood warnings, they can hardly be considered to be experts in how to interpret the information.…”

“…These two variables were selected due to previous, substantial and contradictory, research on the influence of these parameters in the decisionmaking process of citizens at risk (see Casteel, 2016;Potter et al, 2018;Ripberger et al, 2015;Weyrich et al, 2018). These two variables were selected due to previous, substantial and contradictory, research on the influence of these parameters in the decisionmaking process of citizens at risk (see Casteel, 2016;Potter et al, 2018;Ripberger et al, 2015;Weyrich et al, 2018).…”

“…Previous research on IBWs and risk communication have used responses to hypothetical warning situations as a rough proxy for actual behavioural intentions to real warnings based on the theory of planned behaviour (TPB) (see Casteel, 2016;Morss et al, 2016;Potter et al, 2018;Ripberger et al, 2015). Previous research on IBWs and risk communication have used responses to hypothetical warning situations as a rough proxy for actual behavioural intentions to real warnings based on the theory of planned behaviour (TPB) (see Casteel, 2016;Morss et al, 2016;Potter et al, 2018;Ripberger et al, 2015).…”

“…Receiving an official flood warning is not enough to guarantee a response from individuals (Casteel, 2016). Stakeholder consultation has found that some citizens fail to understand water hazard messaging, especially the overly technical terms currently used in warnings to express risk and flood magnitudes (National Oceanic and Atmospheric Administration, 2015;O'Sullivan et al, 2012).…”

A skill assessment of techniques for real-time diagnosis and short-term prediction of tornado intensity using the WSR-88D

“…The NWS adjusted its IBW messaging based on this study to use similar phrasing for considerable and catastrophic tag events (WDTD 2016a). Casteel (2016) found similar evidence supporting the use of enhanced language for significant tornadoes. Increased specificity also was shown to be linked to increased rates of protective action by Naegle and Trainor (2012).…”