Digital formats and social networks provide unique opportunities for meteorologists to disseminate weather information to the public, but it comes with a set of challenges. These opportunities and challenges may be enhanced when applied to a younger demographic, which acquires information from different platforms than the traditional sources the older demographics utilize. There is a vast amount of literature that focuses on weather dissemination, weather information sources, and risk perception; however, there is a lack of emphasis on 18 to 24 year olds. The first two parts of this dissertation attempted to fill this lack of knowledge on 18 to 24 year olds by conducting interviews at several college campuses to gain rich knowledge of the daily processes involving weather information and determine their understanding of weather graphics. Participants cited checking the weather forecast pretty frequently but utilized non-traditional sources for the weather forecast. It was also determined that participants lacked an understanding of weather products. The last part of this dissertation attempted to obtain a better understanding of the public’s weather knowledge and self-perceived weather knowledge. This study compared the public to those who actively follow specialty weather pages. In addition, how severity impacts decision-making and confidence in decision-making was evaluated. Followers of specialty weather pages had higher self-perceived and assessed weather knowledge. It was also determined that the public is more likely to adhere to recommendations from meteorologists, and that the correlation between self-perceived weather knowledge and confidence is weak.

An association was tested between the presence of a television weather broadcaster on-screen and viewers’ likelihood to seek shelter, measured via risk perception and preventative behavior. Social networking websites were used to recruit respondents. Four clips of archived severe weather videos, one pair (on-screen and off-screen broadcaster) using the reflectivity product and another pair (on-screen and off-screen broadcaster) using velocity product, were presented to participants. Viewers’ trust and weather salience were also quantified for additional interactions. A relationship between viewers’ risk perception (preflectivity = 0.821, pvelocity = 0.625) and preventative behavior (preflectivity = 0.217, pvelocity = 0.236) and the presence of the broadcaster on-screen was not found. The reflectivity product was associated with higher risk perception and preventative behavior scores than the velocity product (prp = 0.000, ppb = 0.000).

Effective risk communication in the weather enterprise requires deep knowledge about the communities that enterprise members serve. This includes knowledge of the atmospheric and climate conditions in these communities as well as knowledge about the characteristics of the people living in these communities. Enterprise members often have access to data that facilitate the first type of knowledge, but relatively little social or behavioral data on the populations they serve. This article introduces an effort to overcome these challenges by developing a database of community statistics and an interactive platform that provides dynamic access to the database. Specific emphasis is given to one set of statistics in the community database: estimates of tornado warning reception, comprehension, and response by county warning area in the contiguous United States. Exploration of these estimates indicates significant variation in reception and comprehension across communities. This variation broadly aligns with tornado climatology, but there are noticeable differences within climatologically comparable regions that underline the importance of community-specific information. Verification of the estimates using independent observations from a random sample of communities confirms that the estimates are largely accurate, but there are a few consistent anomalies that prompt questions about why some communities exhibit higher or lower levels of reception, comprehension, and response than models suggest. The article concludes with a discussion of next steps and an invitation to use and contribute to the project as it progresses.

This research estimated the spatial-temporal patterns of tornadoes in the continental United States from 1950-2019 using the National Weather Service Storm Prediction Center’s Severe Weather GIS (SVRGIS) database. This study employed Space-Time Cube Analysis and Linear Kernel Density (Kernel Density Linear Process, (KDLP)) rather than the standard Kernel Density Estimation (KDE) approach; to evaluate whether tornado hotspot locations and intensities shift over time. The first phase of the study utilized KDLP to map changes in tornado hotspots and qualitatively assess decadal shifts in hotspot locations and intensities by occurrence and magnitude between decades using ArcGIS Pro and CrimeStat. Next an Emerging Hot Spot Analysis (EHSA) was employed to identify the changes in tornado occurrence and magnitude. ESHA results identified, by both occurrence and magnitude, significant intensifying hot spots in the Southeast region and diminishing hot spots in the Great Plains indicating an east-south-east shift.

No description available.

This thesis explores the relationship between surface elevation roughness and tornado frequency throughout the eastern United States. It builds upon previous studies which demonstrated a negative relationship between roughness and tornado frequency for the Great Plains and Arkansas. A generalized linear model with tornado frequency as the response variable and roughness and population density as the predictors is generated. This model demonstrates that increased roughness is associated with decreased tornado frequency at the scale of the entire eastern United States, especially where roughness is greater than 20 meters. The methods are also performed for 13 smaller regions within the eastern US, but an effect of roughness is only confirmed for the regions encompassing the Great Lakes and central Appalachians. From these results, it is concluded that mountain ranges, where roughness exceeds 20 meters, clearly inhibit tornado activity, but there is little evidence that smaller terrain variations have the same effect.

Between 2011-2021, violent tornadoes accounted for an average of 65% of all tornado-related fatalities. The Violent Tornado Parameter (VTP), created in 2018, attempts to address this forecast problem but has issues with false alarms. Storm Relative Helicity has historically been used in tornado forecasting. Recent studies have shown the 0-500 m effective layer SRH (ESRH) has skill in discerning significantly tornadic events from those that are not. This study explored the effects of incorporating 0-500 m ESRH into the VTP and issues relating to the parameter’s false alarm rate by examining RUC/RAP forecast soundings for 302 U.S. tornadic events (83 violent, 122 strong, 97 weak) from 2011 to 2020, along with test data from 2021. Overall, the study found that 0-500 m ESRH has skill in forecasting violent tornadoes, and that both the 0-3 km MLCAPE and 0-3 km Lapse Rate terms raised the parameter’s false alarm rate.

Catastrophic wind events can play an important role in the stand structure and composition in Bottomland Hardwood Forests. Regeneration and stand structure following these events depends on a variety of factors, including disturbance severity, past land use, and post-disturbance management. This study revisits a 2004 survey conducted at Mermet Lake State Fish and Wildlife Area in Southern Illinois following a tornado and subsequent salvage logging operation. We established 164 plots on four different disturbance types as mapped by the original survey: Undisturbed, Transition, Wind Damaged Only, and Wind Damaged Salvaged. The objective of this study was to see how recovery differed among these. Data collected included density, basal area, and Shannon’s H, as well as visual evidence of remaining soil rutting resulting from the salvage logging operation, tree height as a metric for productivity, and invasive percent cover. There were slight but significant differences in the densities, basal area, and diversity among disturbance types, although diameter distributions revealed similar age distributions and there was no impact of the salvage logging on productivity. Evidence of soil rutting was still present, adding to microsite diversity that contributed to the significantly higher species diversity of Wind Damaged Salvaged areas. The proportion of Quercus spp. in both Wind Damaged Only and Wind Damaged Salvaged areas was lower than in Undisturbed and Transition areas, while the proportion of other species, including Fraxinus pennsylvanica and key bottomland taxa Salix spp., Taxodium distichum, and Nyssa aquatica, were higher. Invasive non-native species cover was higher in Wind Damaged Salvaged and Wind Damaged Only areas than in Transition and Undisturbed but was confined to forest edges and did not differ between Wind Damaged Salvaged and Wind Damaged Only areas. The results indicate that twenty years after the disturbance, forest structure is still recovering in tornado-damaged areas and has shifted in composition away from Quercus toward domination by Acer spp., Ulmus spp., Fraxinus pennsylvanica, and Liquidambar styraciflua species in both Wind Damaged Only and Wind Damaged Salvaged areas. The salvage logging operation did not have any negative impacts on forest recovery and supported biodiversity by further diversifying overstory community composition to include key wetland species that support the conservation area’s bottomland restoration efforts. Active management should be considered in both Wind Damaged Only and Wind Damaged Salvaged areas to prevent the spread of non-native species and ensure the persistence of Quercus and other key bottomland species in support of conservation objectives.

Tornado intensity and impacts vary drastically across space, thus spatial and statistical analyses were used to identify patterns of tornado severity in the Southeastern United States and to assess the vulnerability and estimated recurrence of tornadic activity. Records from the Storm Prediction Center's tornado database (1950-2014) were used to estimate kernel density to identify areas of high and low tornado frequency at both the regional- and state-scales. Return periods (2-year, 5-year, 10-year, 25-year, 50-year, and 100-year) were calculated at both scales as well using a composite score that included EF-scale magnitude, injury counts, and fatality counts. Results showed that the highest density of tornadoes occur in Alabama, Mississippi, and Arkansas, while the highest return period intensities occur in Alabama and Mississippi. Scaledependent analysis revealed finer details of density and intensity for each state. Better communication of high hazard areas and integration into existing mitigation plans is suggested.

Tornadoes are occurring with increased frequency in Oklahoma. Emergency preparedness planning is essential to decreasing individuals' risks of injury or death from a tornado. Research on immigrant Hispanics' knowledge and perceptions of emergency preparedness is limited. The purpose of this study was to explore the perceptions and lived experiences of immigrant Hispanics who had experienced a tornado or other crisis weather conditions in Oklahoma during spring of 2013. The research questions explored their perceived risk for injury and knowledge of tornado preparedness planning. The health belief model provided the theoretical underpinnings for this qualitative phenomenological study. Semi structured interviews were conducted with a purposeful sample of 10 immigrant individuals living in and around Oklahoma City, Oklahoma. Data were subjected to triangulation and analyzed to identify themes and patterns. Findings indicated that immigrant participants had experienced multiple tornadoes, routinely sought shelter during a tornado, and 50% had created a family emergency plan and supply kit because of their experience with tornadoes and perceived risk for injury. Identified barriers to preparedness planning were language barriers and lack of information on natural disaster preparedness. Recommendations included conducting public health outreach and establishing multidisciplinary partnerships within communities to provide cultural and linguistically appropriate disaster preparedness information to immigrant individuals. Findings provide public health practitioners with the ability to improve access and dissemination of preparedness planning information that may promote positive social change by decreasing immigrants' risk of injury and death.