Field research to application: a study of human response to the 2011, Joplin tornado and its impact on alerts and warnings in the USA

Natural Hazards - An EF-5 tornado occurred on May 22, 2011, in the populated area of Joplin, Missouri, causing 161 fatalities and over 1000 injuries. A conceptual model of protective action...     

Hindcasting community-level building damage for the 2011 Joplin EF5 tornado

Resiliency of communities prone to natural hazards can be enhanced through the use of risk-informed decision-making tools. These tools can provide community decision makers key information, thereby providing them the ability to consider an array of mitigation and/or recovery strategies. The Center for Risk-Based Community Resilience Planning, headquartered at Colorado State University in Fort Collins, Colorado, developed an Interdependent Networked Community Resilience (IN-CORE) computational environment. The purpose of developing this computational environment is to build a decision-support system, for professional risk planners and emergency responders, but even more focused on allowing researchers to explore community resilience science. The eventual goal was being to integrate a broad range of scientific, engineering and observational data to produce a detailed assessment of the potential impact of natural and man-made hazards for risk mitigation, planning and recovery purposes. The developing computational environment will be capable of simulating the effects from different natural hazards on the physical and socioeconomic sectors of a community, accounting for interdependencies between the sectors. However, in order to validate this computational tool, hindcasting of a real event was deemed necessary. Therefore, in this study, the community of Joplin, Missouri in the USA, which was hit by an EF-5 tornado on May 22, 2011, is modeled in the IN-CORE v1.0 computational environment. An explanation of the algorithm used within IN-CORE is also provided. This tornado was the costliest and deadliest single tornado in the USA in the last half century. Using IN-CORE, by uploading a detailed topological dataset of the community and the estimated tornado path combined with recently developed physics-based tornado fragilities, the damage caused by the tornado to all buildings in the city of Joplin was estimated. The results were compared with the damage reported from field studies following the event. This damage assessment was done using three hypothetical idealized tornado scenarios, and results show very good correlation with observed damage which will provide useful information to decision makers for community resilience planning.     

US tornado fatalities in motor vehicles (1991–2015)

Motor vehicles historically have been dangerous locations to shelter in during tornado events. Throughout the twentieth century, motor vehicle design has become safer while tornado forecasting has become better understood. Despite such advances, tornado fatalities in motor vehicles still occur today, and some events periodically result in high numbers of deaths (e.g., ten motor vehicle occupants were killed by a single tornado in Garland, Texas, in 2015). We seek to examine all US tornado-induced motor vehicle fatalities documented between 1991 and 2015. Our findings indicate that motor vehicle fatalities have not significantly changed during this study period. We attribute annual fatality totals to persons lacking awareness of impending dangers coupled with numbers of significant tornado events for a given year. We find most fatalities result when vehicles are lofted or passengers are ejected, and this most typically occurs at the EF3–EF5 intensity thresholds. Fatalities that occur at weaker tornado winds (EF0–EF2) are most often attributed to collapsing debris (mostly trees) on vehicles. Spatially, motor vehicle fatalities are greatest in the Deep South and southern Great Plains regions where overall tornado and nighttime tornado frequencies are greatest. Some of the largest motor vehicle fatality events have resulted from tornadoes not being distinctly visible to motorists; such events have been characterized by tornadoes occurring at night or by tornadoes not appearing as “classic funnels.”     

Tornado fatalities and mobile homes in the United States

Fatalities from tornadoes have declined dramatically over the last century in the United States. Despite the overall reduction in tornado lethality, fatalities from mobile homes remain high. In fact, research suggests that the likelihood of a fatality in a mobile home is ten times or more than that in a permanent home. This study examines possible explanations of the mobile home tornado problem, including the potential for concentration of these homes in tornado prone states, the relation to Fujita Scale rating, and incidence during the day. We find that mobile home fatalities are concentrated in the Southeastern US, significantly more likely in weaker tornadoes, and occur disproportionately at night.     

Nontornadic convective wind fatalities in the United States

A database was compiled for the period 1977–2007 to assess the threat to life in the conterminous United States from nontornadic convective wind events. This study reveals the number of fatalities from these wind storms, their causes, and their unique spatial distributions. Nontornadic convective wind fatalities occur most frequently outdoors, in vehicles including aircraft, or while boating. Fatalities are most common in the Great Lakes and Northeast, with fewer fatalities observed in the central United States despite the climatological peak in severe thunderstorms in this region. Differences in fatality locations between tornadoes and nontornadic convective wind events highlight the unique combination of physical and social vulnerabilities involved in these deaths. Understanding these vulnerabilities is important to future reduction of nontornadic convective wind fatalities.     

Severity scale for tornadoes

Tornadoes are the most destructive winds created by nature. Sometimes tornadoes are strong enough to destroy most things in their path. These types of tornadoes are few compared to all tornadoes confirmed/reported. Currently, existing scales describe severity levels in terms of intensity/magnitude, and they are not sufficient to clearly distinguish the severity level. Several discrepancies between various sources of information complicate the interpretation of trends in tornado data. As a solution to these inconsistencies, a technique is required to compare the severity level of tornadoes. Impact factors, such as the number of fatalities, number of injuries, number of homeless, affected population, affected area, and cost of damage, can be considered to evaluate the severity levels. Prior experience, preparedness, awareness, evolving technology, mitigation methods, and early warning systems may minimize the number of fatalities and injuries. Models are used to identify which of the above factors should be considered in a severity scale to indicate the seriousness of tornadoes. However, the lack of data prevents an in-depth analysis of tornado severity. Extreme value theory is used to study potential severity levels of tornadoes. This paper attempts to develop an initial severity scale for tornadoes, which is a primary stage to develop a multi-dimensional severity scale. This common scale provides the criteria to rank tornadoes and allows the impact of one tornado to be compared to the impact of another tornado. Further, the scale allows the impact of a tornado to be compared to any type of natural disaster that occurs.     

An examination of rip current fatalities in the United States

This study analyzes fatalities caused by rip currents in the conterminous United States for the period 1994–2007. Results include the frequency of fatalities from rip currents, their cause, and their unique spatial distributions. An analysis of historical hazard event data illustrate that, on average, 35 people reportedly die from rip currents each year in the United States. Also, similar to other hazard events where unique differences in gender vulnerability have been found, men are over six times more likely to fall victim to a deadly rip current than females. Rip current fatalities are most common in the southeastern United States, with a nonuniform spatial distribution along other Atlantic, Pacific, and Great Lakes coastlines. Physical vulnerabilities are suggested as the primary cause for the unique fatality distribution found. Temporally, summer season weekends are shown to have the more fatalities than any other time of the year. A classification scheme was developed to categorize synoptic-scale weather conditions present during deadly rip current events. More than 70% of all rip current fatalities are associated with onshore winds. Specifically, a rip current fatality is most likely when a surface high pressure system creates these onshore winds. The quality of the fatality reporting database available for researchers is also assessed.     

Avalanche fatalities in the western United States: a comparison of three databases

Reported avalanche fatalities in the United States increased markedly through the latter half of the twentieth century, a result of the increasing popularity of winter sports. Despite this increase, the literature concerning US avalanche fatalities is sparse. This paper presents a comparison of three US databases containing avalanche fatality information: Storm Data, the West Wide Avalanche Network (WWAN) dataset, and the National Avalanche Database (NAD). The frequency of avalanche fatalities, their temporal trends, spatial distributions, and the demographic characteristics of the victims were analyzed in each database for the years 1998–2009 for the US mountainous west. The data were then pooled to arrive at an estimate of avalanche fatality frequency in the United States for the study period. While the results indicate a considerable amount of overlap between the datasets, Storm Data reports fewer avalanche fatalities than both the WWAN and NAD datasets. All three datasets report a maximum of fatalities in January and display three spatial maxima: the Rocky Mountains of west-central Colorado, the intermountain region from central Utah through Idaho to west-central Montana, and the northern Cascade Ranges of Washington; however, a large void appears in the Storm Data records in the vicinity of the Montana maximum. These maxima result from a juxtaposition of avalanche hazard in these mountainous environments with a high concentration of winter sports activities.     

Manufactured home building regulations and the February 2, 2007 Florida tornadoes

The Department of Housing and Urban Development (HUD) and the state of Florida implemented new wind load and tie-down regulations for manufactured homes following Hurricane Andrew. This article examines the effect of the new regulations on the likelihood that occupants of mobile homes would survive a tornado. On February 2, 2007, three tornadoes struck central Florida, resulting in 21 deaths in Lake County, all in manufactured homes. The deaths occurred almost exclusively in homes rated as leveled by the county tax appraiser. Manufactured homes built to the new regulations, however, were significantly less likely to be leveled. Regression analysis finds that manufactured homes built to the post-Andrew requirements were 79% less likely to be leveled than homes built prior to the HUD Code in 1976, and 68% less likely to be leveled than homes built after 1976 but before the 1994 wind load regulations. Construction of all manufactured homes in the tornado paths to the wind load and tie-down requirements could have reduced fatalities by 70%.

An analysis of coastal and inland fatalities in landfalling US hurricanes

Improvements in hurricane forecasts allowing for more timely evacuations from storm-surge zones are credited with reducing lethality of US landfalling hurricanes. The deadly reach of a hurricane, however, is not limited to storm-surge zones. About 80% of direct US hurricane fatalities since 1970 occurred outside of landfall counties, with most of these fatalities caused by inland flooding. We construct a geographic information system database combining the location and cause of fatalities, estimated wind speeds, and rainfall amounts for the entire track of the storm for landfalling US hurricanes between 1970 and 2007. We analyze the determinants of total fatalities and deaths due to freshwater drowning and wind. Inclusion of inland fatalities results in no downward trend in lethality over the period, in contrast to prior research. Local storm conditions significantly affect lethality, as one-inch and one-knot increases in rainfall and wind increase total fatalities by 28 and 4%. Rainfall significantly increases freshwater-drowning deaths and is insignificant for wind deaths, while the opposite relation holds for wind speed. While coastal counties do not exhibit a significantly higher amount of lethality risk versus inland counties for total or wind-driven fatalities, freshwater-drowning fatalities occur most frequently in inland counties along the center of the storm path and its outer county tiers as we have defined them.     

Synoptic features and environmental conditions of the tornado outbreak on March 22, 2013 at Brahmanbaria in the east-central region of Bangladesh

This study evaluates the synoptic features and environmental conditions of Brahmanbaria tornado event that caused 36 fatalities, 388 injuries and huge damages of properties on 22 March, 2013. Various factors for initiation of that terrific event are investigated through analysis JRA-55 reanalysis (50 km horizontal resolution) data and Multi-functional Transport Satellite images by Japan Meteorological Agency. In addition, radar images, radiosonde data and three hourly synoptic data of Bangladesh Meteorological Department are used to verify the reanalysis data. The genesis of the tornadic storm is identifiable in the most unstable part of the study region. The satellite observations are found to useful to identify the location of convection occurrence region. The half hourly satellite images identify that the convection initiation started at the convergence area and the systems intensify and organize by the continuous moisture supply from the Bay of Bengal. Lower-level convergence coupled with strong wind shear and humidity gradient lift moist air aloft to trigger deep convection and the severe storm occurred. Energy Helicity Index seems a good predictor parameter for this specific case study.     

Tornado hazards on June 23 in Jiangsu Province,China: preliminary investigation and analysis

This paper reported a tornado hazard happened on June 23, 2016, in Yancheng city, Jiangsu Province. The moving footprint of this huge tornado was from west to east. Shuoji, Chenliang, Goudun, Banhu, Xingou, Wutan towns in Funing district and Sheyang town in Sheyang district were severely hit by this tornado. This tornado along with rainstorm and hailstorm had claimed 99 lives and caused more than 3800 flats to collapse as well as damaged 48 high-voltage circuits. As the cold air from northwest met the subtropical high pressure system that forms over relatively cool water bodies (i.e., Indian and Pacific Oceans), such a powerful meteorological phenomenon was initiated. The strong connective airflow intensified the development of this tornado. Based on the preliminary investigation and analysis of this tornado, cost-effective timber structures with adequate anchorage of the framing to foundations and adequate connection between walls and roofs may be recommended to ensure occupants safety and reduce potential damage in these extreme wind events. Additionally, it is suggested to utilize early warning system along with geographical information system (GIS), Global Positioning System (GPS), and remote sensing (RS) (3S) to monitor and precast the occurrence of rainfall, hailstorm, and tornado hazards in future.

     

Implications of the 2011 Tuscaloosa EF4 tornado for shelter and refuge decisions

This research provides an overview and discussion of language used in tornado safety recommendations along with development of a rubric for scaled tornado safety recommendations. Residents living in affected areas and those temporarily housed at relief stations were surveyed to collect information on their experiences during a 2-week period following the April 27, 2011 Tuscaloosa, Alabama EF4 tornado. Respondents were asked about their refuge plans during the storm and about any future changes to those plans. A specific focus of this research evaluated the adequacy of each respondent’s plan. Each refuge plan was compared using a tornado refuge rubric developed through the use of enhanced Fujita (EF) scale degree of damage ratings for available damage indicators. There was a significant difference in the counts of refuge adequacy for Tuscaloosa residents when holding the locations during the April 27 tornado constant and comparing adequacy ratings for weak (EF0–EF1), strong (EF2–EF3), and violent (EF4–EF5) tornadoes. There was also a significant difference when comparing the future tornado refuge plans of those same participants to the adequacy ratings for weak, strong, and violent tornadoes. This research introduces renewed discussion on proper refuge and shelter alternatives for days when violent tornadoes are forecasted.     

Utilizing synoptic climatological methods to assess the impacts of climate change on future tornado-favorable environments

Previous research into the impacts of climate change on severe mid-latitude weather has been limited by the spatial resolution of many important variables in global climate model output. By utilizing synoptic climatological methods, however, this research takes an entirely different approach. Using a six-step process that includes principal components analysis, cluster analysis, and discriminant function analysis, this study first creates a continental-scale map pattern classification at three levels of the atmosphere, from geopotential height and temperature fields. These patterns are then associated to historic F2 and stronger United States?? tornado days using binary logistic regression. Using output data from two GCMs, spanning five different model emissions scenarios, this synoptic climatology of tornadoes is then utilized in order to project the changes in the frequency and seasonality of tornadic environments due to a changing climate. Results indicate that F2 and stronger US tornado days will increase anywhere from 3.8 to 12.7% by the 2090s. The majority of this increase is likely to be manifested in the earlier part of the tornado season. In addition to the shift in seasonality, a broadening of the peak tornado season is also noticed under some scenarios. Geographically, portions of the Northern and Central Plains, the High Plains, the Lower Great Lakes, the Mid-Atlantic States, and the Southeast are projected to experience an increase in tornado days under some future scenarios. The Upper Great Lakes states and the Southern Plains are projected to experience a decrease in tornado days.     

A qualitative study of mobile home resident perspectives on tornadoes and tornado protective actions in South Carolina,USA

Occupants of mobile or manufactured homes in the United States of America (USA) are highly exposed and susceptible to injury or death from tornado hazards. This problem is most pronounced in the southern and eastern USA, where tornadoes are frequent and mobile homes comprise upwards of 15 % of the housing stock. Recognizing this vulnerability, emergency management entities and the USA National Weather Service often recommend that mobile home residents evacuate to a nearby sturdy building or a specially-built tornado shelter when tornadoes threaten their communities. Previous research suggests, however, that only 30 % of residents follow this recommendation. In this research I aim to provide insight as to why many mobile home residents seldom undertake the suggested course of action for tornadoes. Using excerpts from twenty semi-structured interviews conducted during 2013 in South Carolina, I show that some individuals understand physical characteristics of tornadoes very differently than experts do. In addition, mobile home residents may also hold views that differ from experts about the ability of their homes to withstand tornadic winds and debris. Even if mobile home occupants pay close attention to thunderstorm hazards and might be willing to evacuate, they may prioritize protective actions for lightning or flash flooding over those recommended for tornadoes. Finally, the interviews reveal that there is much confusion over where to go, when to leave, and which route to take to arrive safely at a sheltering place for tornado hazards. I discuss some of the potential ramifications of the findings for theory and practice and suggest how future research might build on this work.     

http://www.sciencedirect.com/science/article/pii/S1674987115000869

The predictability of dangerous atmospheric phenomena such as tornado outbreaks has generally been limited to a week or less. However, recent work has demonstrated the importance of the Rossby wavetrain phasing over the United States in establishing outbreak-favorable environments. The predictability of Rossby wavetrain phasing is strongly related to numerous climate-scale interannual variability indices, which are predictable many months in advance. To formalize the relationship between interannual variability indices and seasonal tornado outbreak frequency, indices derived from monthly mean Northern Hemisphere 500-hPa and 1000-hPa geopotential height fields and Ni?o 3.4 indices for ENSO phase were compared to annual tornado outbreak seasonal frequencies. Statistical models predicting seasonal outbreak frequency were established using linear(stepwise multivariate linear regressione SMLR) and nonlinear(support vector regressione SVR) statistical modeling techniques.The stepwise methodology revealed predictors that are important in establishing outbreak-favorable environments at long lead times. Additionally, the results of the statistical modeling revealed that the nonlinear SVR technique reduced root mean square errors produced by the control SMLR technique by 28% and provided more consistent forecasts. A preliminary physical analysis revealed that years with high outbreak frequencies were associated with the presence of 500-mb troughs over the central and western US during the peak of outbreak season, while lower frequencies were consistent with ridging over the US or northwest flow over the Plains. These patterns support the results of the statistical modeling, which demonstrate the utility of geopotential height variability as a predictability measure of outbreak frequency.     

Why relatively fewer people died? The case of Bangladesh’s Cyclone Sidr

Cyclone Sidr, a Category IV storm, struck the southwestern coast of Bangladesh on November 15, 2007 killing 3,406 people. Despite a similar magnitude, Sidr claimed far fewer lives than Cyclone Gorky, also a Category IV storm, which struck Bangladesh in 1991 causing an estimated 140,000 fatalities. The relatively low number of deaths experienced with Sidr is widely considered the result of Bangladesh government’s efforts to provide timely cyclone forecasting and early warnings, and successful evacuation of coastal residents from the projected path of Cyclone Sidr. Using information collected from both primary and secondary sources, this study identified several other reasons for the unexpectedly lower mortality associated with Cyclone Sidr relative to Cyclone Gorky. Fewer casualties may be attributed to a number of physical characteristics of Cyclone Sidr, such as duration of the storm and storm surge, landfall time and site, varied coastal ecology, and coastal embankment. This article recommends improvements to the cyclone warning systems, establishment of more public cyclone shelters, and implementation of an education campaign in coastal areas to increase the utilization of public shelters for future cyclone events.     

Severe tornadoes on the Caribbean coast of Colombia since 2001 and their relation to local climate conditions

Tornadoes have been reported in various places around the world. The United States has the greatest number of tornado reports. In South America, tornadoes have been reported in Argentina and neighboring countries, such as Chile, Brazil, and Uruguay. There are no reports of tornadoes in Colombia in the worldwide databases. The first reported tornado event in Colombia took place in 2001. Since then, four tornados have affected the northern part of Colombia. The aim of this study is to characterize the events reported on the Caribbean coast of Colombia and their relation to local climate conditions. Before 2001, we had no knowledge regarding tornadoes in this area. However, during the past 10?years, these atmospheric phenomena have occurred in Barranquilla and the surrounding metropolitan area. Worldwide databases on tornadoes have not registered any such events in this part of South America. A review of the atmospheric information was conducted to determine the influence of air temperature increases on tornado formation. This study reveals that tornadoes have appeared between May and September, the months during which the city experiences the hottest temperatures of the year. The most significant tornado took place on September 15, 2006. This tornado lasted 15?min and travelled almost 10?km. Of the four registered tornadoes, this was the only one to affect the residential area of the city. The other three affected only the suburbs located in the surrounding metropolitan area. The most recent phenomenon related with tornadoes took place between July and August of 2010, during which three tornadoes could have potentially formed. However, a vortex never made contact with the ground. This meteorological analysis is very basic because climate information for these areas is limited. Still, what information we have reveals conditions that are typical of tornado formation: a mass of cold air combined with high air temperatures in a specific area. The data analysis reveals that tornados have occurred between May and June. These months correspond to the period characterized by the highest temperatures: average temperatures of 28.2?°C and maximum temperatures of 33.2?°C. This is also the period characterized by the greatest relative humidity and precipitation (84?% and 50?mm, respectively). Because the tornadoes reports only appeared in the last 10?years, it is not possible to determine whether there is a realistic relationship between their occurrence and large-scale climatic change. This article characterizes tornadoes as a new environmental threat and not an isolated phenomenon for this part of Colombia. Tornadoes in this region should thus be included in global databases.     

Debris flows and their toll on human life: a global analysis of debris-flow fatalities from 1950 to 2011

Debris flows cause significant damage and fatalities throughout the world. This study addresses the overall impacts of debris flows on a global scale from 1950 to 2011. Two hundred and thirteen events with 77,779 fatalities have been recorded from academic publications, newspapers, and personal correspondence. Spatial, temporal, and physical characteristics have been documented and evaluated. In addition, multiple socioeconomic indicators have been reviewed and statistically analyzed to evaluate whether vulnerable populations are disproportionately affected by debris flows. This research provides evidence that higher levels of fatalities tend to occur in developing countries, characterized by significant poverty, more corrupt governments, and weaker healthcare systems. The median number of fatalities per recorded deadly debris flow in developing countries is 23, while in advanced countries, this value is only 6 fatalities per flow. The analysis also indicates that the most common trigger for fatal events is extreme precipitation, particularly in the form of large seasonal storms such as cyclones and monsoon storms. Rainfall caused or triggered 143 of the 213 fatal debris flows within the database. However, it is the more uncommon and catastrophic triggers, such as earthquakes and landslide dam bursts, that tend to create debris flows with the highest number of fatalities. These events have a median fatality count >500, while rainfall-induced debris flows have a median fatality rate of only 9 per event.     

Tropical cyclone-tornado casualties

Landfalling tropical cyclones often produce tornadoes. This study investigates how hazardous these tornadoes are to human life by analyzing the resultant casualties, which includes fatalities and injuries. From 1995 to 2009, 63 tropical cyclones made landfall in the United States producing a reported 1,139 tornadoes. Most tornadoes resulted in no casualties but a few extreme cases indicate that the potential exists for a substantial number of casualties. Temporal and spatial analyses indicate that most casualties occur when and where the physical risk of tornadoes is elevated.