An Agricultural Perspective on Severe Hail Storm Vulnerability and Warning Message Efficacy

Hail storms cause billions of dollars in damage each year across the U.S. Most of the hail events that attract media coverage are those which cause extensive damage to vehicles or buildings in populated areas, but less attention is given to hail storm impacts on farm land and other agricultural ventures, despite the importance of crop yields on local communities and the livelihoods of the growers themselves. To learn more about the agricultural perspective of the risks and vulnerabilities associated with hail storms, as well as any changes in hail storm characteristics over time, an interview study was conducted in Summer 2019 with agriculturalists across eastern Colorado, one of the most active hail regions in the U.S. A sample of twenty agriculturalists was gathered from across eastern Colorado, defined as anywhere east of the foothills of the Rocky Mountains. Participants ranged from small, urbanized vegetable farmers to large-scale wheat growers with tens of thousands of acres and cattle ranchers. The interview implemented the ‘mental models’ approach, with the intention of learning the ingrained views agriculturalists have regarding hail storms, as well as the Protective Action Decision Model, which aimed to assess reception and responses to severe hail warning messages. Not surprisingly, most interviewees view hail storms in a negative light, as a hazard which can cause significant impacts on their crop yields and income. An interviewee’s vulnerability was assessed through exposure, or how frequently hail storms were perceived to occur on his or her property on any given year, and sensitivity, or the degree to which a participant is able to deal with the effects of a hail storm given a variety of non-meteorological factors. Participants generally fell into two camps in rating their exposure to severe hail storms: some perceived their exposure as extremely likely, while others gave a very low chance of severe hail happening on their property on a given year. In addition, most participants did not note any change in their exposure or the frequency of severe hail storms over time, nor in the size of hail stones observed. Those who perceived their sensitivity to hail storms to be toward the higher end of the spectrum cited factors such as economic loss, the types of crops grown, and the inability to protect crops from hail. The agriculturalists also tended to highlight that hail volume is of greater concern than hail size. For example, small hail in large quantities, or small hail driven by a strong wind, were often mentioned as greater risks to crops and livestock than hail of larger sizes that fell at a lesser volume. This finding calls into question the current severe hail threshold used by the Storm Prediction Center of hail that is at least 1.0” in diameter, as this delineation may not be relevant to all people; the agriculturalists interviewed tended to want information about the expected hail volume or concurrent wind speeds. The preferred sources of forecast and warning messages for hail were also gleaned from the interviews. The agriculturalists interviewed tend to gather information primarily from apps, although empirical observations of threatening weather often guide their decision-making actions. Overall, agriculturalists noted the perpetual nature of hail storms and the lack of feasible strategies to protect crops and property, leading to disheartened, worrisome, or in some cases apathetic feelings. This work represents the first look at the perceptions of severe hail storms, with the sector of society that is arguably the most impacted by them, and results can be used to both increase awareness and motivate improved hail risk communication to the agricultural community of eastern Colorado and beyond.