Intense precipitation events (IPE; 99th percentile) in the southeastern United States from 1950 to 2016 were analysed temporally, spatially, and synoptically. The study area was partitioned into latitudinal and physiographic regions to identify subregions that experienced significant changes in IPE frequency or intensity. Furthermore, the spatial synoptic classification (SSC) was used to ascertain what surface weather types are associated with IPEs. Additionally, in conjunction with the SSC, surface forcing mechanisms for the 30 most extreme subregional IPEs were studied to uncover the surface synoptic conditions responsible for IPEs. Results revealed that IPEs increased in frequency and intensity on an annual basis for the southeastern United States. Seasonal results indicated that IPE frequency only increased in the fall. Subregional results reveal that latitudinally, IPEs became more common in the northern latitudes of the study area, while physiographically, significant increases in IPE frequency were most pronounced in areas inland from the Atlantic Coastal Plain. An increase in the annual number of IPEs associated with moist tropical (MT) days was identified across the study area, but was more prevalent in the central and north central latitudinal regions, and areas inland from the Atlantic Coastal Plain outside of the Appalachian Mountains. This MT increase was possibly caused by more common northwards and inland intrusion of these types of IPEs. While moist moderate (MM) and transitional (TR) days were most commonly associated with IPEs, these weather types did not have significant trends. The surface forcing mechanisms most commonly associated with the strongest IPEs were tropical events, followed by stationary fronts and concentric lowpressure systems.

Hurricanes Isaac (2012), Harvey (2017), and Irma (2017) were storms with different geophysical characteristics and track forecast consistencies. Despite the differences, common themes emerged from the perception of track forecasts from evacuees for each storm. Surveys with a mixture of closed and open-ended responses were conducted during the evacuations of each storm while the storm characteristics and decision-making were fresh in the minds of evacuees. Track perception accuracy for each evacuee was quantified by taking the difference between three metrics: perceived track and official track (PT − OT), perceived track and forecast track (PT − FT), and home location and perceived track (HL − PT). Evacuees from Hurricanes Isaac and Harvey displayed a tendency to perceive hurricane tracks as being closer to their home locations than what was forecast to occur and what actually occurred. The large sample collected for Hurricane Irma provided a chance to statistically verify some of the hypotheses generated from Isaac and Harvey. Results from Hurricane Irma confirmed that evacuees expected a storm to be closer to their home locations after controlling for regional influences. Furthermore, participants with greater previous hurricane experience perceived a track as being closer to their home locations, and participants residing in zip codes corresponding with nonmandatory evacuation zones also perceived tracks as being closer to their home locations. These findings suggest that most evacuees from hurricanes in the United States appear to perceive storms as being closer to their home locations than they are and overestimate wind speeds at their homes, thus overestimating the true danger from landfalling hurricanes in many storms.

This study evaluated 500mb and 850mb flow patterns as well as surface pressure and 72-hour precipitation characteristics of large areal scale intense precipitation events in the Southeastern United States from 1950-2016. This was attempted using a combination of statistical methods utilizing PCA and cluster analysis as well as a manual classification scheme based on synoptic-scale storm type and formation location. All large-scale events were able to fit within one of five manual classifications: tropical events, frontal events, and three mid-latitude cyclone types: those that formed over the Southeast/Gulf of Mexico, the southern plains, and the Midwest/northern plains. This research builds upon GIS methods of classifying flow characteristics utilizing reanalysis data and has the potential to aide forecasters in identifying setups conducive to large-scale intense precipitation events.

Due to the current use and reliance on tornado warning polygons, several published articles have concentrated on themes related to risk perception and interpretation of risk within and outside of polygons. Despite the general success of warning polygons, not everybody is able to spatially estimate their risk by looking at maps with tornado warning polygons. Using polygons in conjunction with radar images can improve comprehension and better inform protective action decision-making for tornado warnings. Additionally, a potential latent area of research is how past tornado tracks and climatological knowledge about tornado path directions may influence tornado risk perception and protective action decision-making. In this study, we surveyed 1023 individuals across the southeastern United States. Participants were asked to rate their level of concern for a tornadic supercell moving toward two locations. They were also asked to name the direction tornadoes usually come from and travel toward in their counties. Results indicated significantly more concern about the radar reflectivity within the supercell than concern about the location of the hook echo. Additionally, the perceived directions of tornado paths across the region were inaccurate with 75 percent of the sample either not answering, indicating that they did not know the most common direction for tornado paths, or answering that tornadoes travel in uncommon or unrealistic path directions. The Atlanta metropolitan area was used as a case study to illustrate inaccurate perceptions of path directions.

Due to the current use and reliance on tornado warning polygons, several published articles have concentrated on themes related to risk perception and interpretation of risk within and outside of polygons. Despite the general success of warning polygons, not everybody is able to spatially estimate their risk by looking at maps with tornado warning polygons. Using polygons in conjunction with radar images can improve comprehension and better inform protective action decision-making for tornado warnings. Additionally, a potential latent area of research is how past tornado tracks and climatological knowledge about tornado path directions may influence tornado risk perception and protective action decision-making. In this study, we surveyed 1,023 individuals across the southeastern United States. Participants were asked to rate their level of concern for a tornadic supercell moving toward two locations. They were also asked to name the direction tornadoes usually come from and travel toward in their counties. Results indicated significantly more concern about the radar reflectivity within the supercell than concern about the location of the hook echo. Additionally, the perceived directions of tornado paths across the region were inaccurate with 75% of the sample either not answering, indicating that they did not know the most common direction for tornado paths, or answering that tornadoes travel in uncommon or unrealistic path directions. The Atlanta metropolitan area was used as a case study to illustrate inaccurate perceptions of path directions.