Download or read book Reducing Tornado Warning False Alarm Rates Across the National Weather Service Memphis County Warning Area written by Preston Jewel Bradley and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Tornado detection has improved in recent years due, in part, to the deployment of dual-polarization radar technology. Depsite these improvements, false alarm rates (FAR) for tornado warnings remain high over Memphis, TN County Warning Area. The purpose of this research was to use a suite of radar products and storm environmental parameters in an effort to decrease tornado warning FAR over the Mid-South. The Memphis National Weather Service Forecast Office County Warning Area (CWA) serves as the study area for this reseach. Previous research has shown that storm mode and environment can imact FAR. Therefore, by combining radar products and storm environment, tornadic and non-tornadic events could be distinguished and the FAR could be reduced. Results suggest that some combination of rotational velocity and a modifed energy-helicity index that places more emphasis on shear and is sensitive to low convectively available potential energy (CAPE) values might aid in reducing tornado warning FAR. .
Download or read book Verification and Analysis of Impact based Tornado Warnings in the Central Region of the National Weather Service written by Holly B. Obermeier and published by . This book was released on 2014 with total page 99 pages. Available in PDF, EPUB and Kindle. Book excerpt: Tornado warnings are one of the most critical products issued by the National Weather Service (NWS), and favorable verification statistics are desirable. The 2011 NWS statistics for traditional tornado warnings indicate that the probability of detection (POD) is 70%, while the false alarm rate (FAR) is 76%. The recent Joplin, Missouri EF5 tornado event on 22 May 2011, which resulted in massive devastation and loss of life, prompted the NWS to re-evaluate the current tornado warning format. After the Joplin, MO event, the Central Region of the NWS implemented the impact-based tornado warning (IBTW) experiment in 2013. IBTWs consist of tiers including damage tags and impact wording which convey increasing levels of damage. The damage wording within an IBTW is shown to relate to the Enhanced Fujita (EF) Scale. Wording included in non-tagged IBTWs corresponds to EF0-EF2 tornado damage, while the damage wording for tagged IBTWs corresponds to EF3-EF5 tornado damage. This study investigates the accuracy of IBTWs by examining if a tornado occurs during the warning time frame, and whether the resulting damage matches the damage wording in the IBTW. All IBTWs from 1 April 2013 through 30 November 2013 are collected, as well as tornado survey information, including EF Scale intensity, for every tornado which occurred in the Central Region during the same time period. Using these survey data, IBTWs are verified by the intensity of the tornado, if one occurs. POD and FAR statistics are calculated through 2x2 contingency tables for both non-tagged and tagged IBTWs. Results indicate that the majority of both non-tagged and tagged IBTWs are false alarms, and tagged IBTWs have a very low POD. Case studies of several events explore successful and unsuccessful implementation of damage tags, revealing that limitations in current technology and scientific knowledge may contribute to false alarms and missed detections. These findings suggest that more advances in technology and the understanding of tornadogenesis are necessary for more successful implementation of IBTWs.
Download or read book Tornado Preparedness Planning written by United States. National Weather Service and published by . This book was released on 1973 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Danger Zone The Effect of Storm based Tornado Warnings on Expected Casualties written by Michael T. Bilder and published by . This book was released on 2012 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt: For decades, the National Weather Service (NWS) issued tornado warnings on a county-level. As a result, an entire county would be warned, even if only a small portion of the population was in danger. Over-warning for tornado threats can lead to a very dangerous sense of complacency amongst the public. On October 1, 2007, the agency converted to issuing storm-based warnings, through which meteorologists would design a unique warning area (shaped as a polygon) that projects the general path they expect a tornado or potentially tornadic storm cell to take. In theory, this approach limits the warning audience to the part of a county that could be directly impacted by a tornado. Narrowing the warning should reduce the impact of false alarms, as well as enable individuals to better assess the risk of harm and the value of taking shelter, thereby reducing the number of expected tornado casualties. Using regression analysis, this thesis tests to see if the way in which the NWS uses geography to communicate proximity to tornado risk has an effect on expected casualties. The effect of reducing the warning area size is controlled for by incorporating into the model the average county area reduction score for each county tornado event. This variable failed to achieve significance. Consequently, the thesis cannot conclude that the switch to storm-based warnings has had a statistically significant effect on reducing or increasing expected casualties. The lack of significance could be attributed to insufficient data, although the dataset contains nearly all county tornado events since the policy took effect. An alternative explanation is that most of the current warning dissemination systems are incapable of only alerting individuals located within the unique boundaries of the polygon.
Download or read book Severe Weather Climatology for the NWSFO Memphis County Warning Area written by David Gaffin and published by . This book was released on 1995 with total page 15 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The National Weather Service s Polygon Method Warning Dissemination of the Future written by and published by . This book was released on 2005 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The National Weather Service (NWS) is continuously improving its forecasting skills, but forecasters still cannot accurately predict the path of a tornado or a severe thunderstorm. The NWS has developed a new warning system in which the warned area is outlined by a polygon, not a county boundary. The polygon-waming approach is expected to significantly reduce the total square-mile area of warnings not followed by an event, called the False Alarm Area. There are three central issues concerning the failure of the polygon-warning method: I) the size of the counties impacted by a storm, 2) the impact of the new warning system on visual and auditory warning methods, and 3) the communication between the NWS, media, and emergency management. If the polygon-warning method is going to be a practical alternative to the countywarning method, then warning disseminators will have to work together to provide the most consistent method of communicating severe-weather wamings to citizens who are in immediate danger.
Download or read book Disseminating Tornado Warnings to Rural Populations written by Zebulon Charles Wallace and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Tornado warnings are a form of persuasive communication that are intended to motivate people to take protective action. These warnings must reach all of the population exposed to the hazard no matter what time of day it is or where they are located. To accomplish this, multiple platforms are used to disseminate warning information. However, there is little research dedicated to how effective these platforms are in rural communities. Additionally, fatality rates tend to vary among rural communities, particularly between Tornado Alley and Dixie Alley; two high frequency tornado areas of the U.S. The objective of this research is to determine if differences in access, reliance, preference, and trust in tornado warnings can explain patterns in fatality rates between rural communities. Further, this work identifies resilience characteristics underutilized during times of emergency that could promote life-safety protective actions. A series of surveys conducted with National Weather Service forecasters, county-level emergency managers, and residents of communities in both Dixie Alley and Tornado Alley provide the basis for the findings of this research. The results for this work provide forecasters and emergency managers with a scientific basis for evaluating any misalignment of protocols or priorities to insure that the life-saftey goals of warning communications are being met. This dissertation research finds that while variations in platform access, reliance, and trust in sources do exist, residents in rural communities have access to multiple platforms. Encouragingly, the warning messages are not only received, they are understood. In fact, the missing link between an issued warning and residents participating in protective action is the lack of either shelter options or a plan. Residents' awareness of the risk and vulnerabilities they are exposed to are found to be accurate, which provides a strong platform from which to address the preparedness and sheltering needs to enhance community resilience and reduce fatalities associated with tornado events. .
Download or read book Convective Mode Climatology of Tennessee Tornado Events and Effect on National Weather Service Warning Processes written by Kelly Nicole Gassert and published by . This book was released on 2017 with total page 91 pages. Available in PDF, EPUB and Kindle. Book excerpt: Tennessee resides in the Southeastern United States, a region prone to violent tornadoes on a year-round basis. With one of the highest tornado fatality rates in the country, and a climatology that varies across the state, analysis of storms resulting in Tennessee tornadoes is necessary for improving forecasting techniques and decreasing loss of life. This study analyzed convective modes responsible for Tennessee tornadoes from 2003 to 2014 to determine an association with fatalities, seasonality, day and night, tornado magnitude, regionality, and multiple-tornado days. Chi-squared tests were conducted to determine if these patterns were significant. National Weather Service forecasters from the Morristown, Tennessee, Weather Forecast Office (WFO) were interviewed to gain insight into how convective mode affects tornado forecasting and warning procedures. Discrete supercells were the overwhelming producer of tornado-related fatalities, higher-magnitude (≥ EF2) tornadoes, and multiple-day tornadoes. Quasi-linear convective systems (QLCSs) produced only non-fatal tornadoes with magnitudes of ≤ EF2 during the period; however, QLCS tornadoes were more frequent at night and in winter, when the public may have been more vulnerable. Spring was the most tornadic season, but approximately 37% of tornadoes occurred outside of this season. Multiple-tornado days were major contributors to tornado totals, with just over half of the 427 tornadoes occurring on ten days. I found no clear longitudinal gradient of convective mode or tornado characteristics across Tennessee. Chi-squared results indicated a relationship between convective mode tornado production and fatalities, seasonality, day and night, magnitude, and region of Tennessee. Forecasters commented on the relative ease associated with warning for discrete supercells, resulting in higher probability of detection, lower false alarm ratios, and longer lead times when compared to QLCSs. Forecasters shared invaluable information concerning staffing considerations and warning decisions during severe weather events. This mixed-methods approach provided a comprehensive assessment of how convective mode affects tornado production and warning procedures, contributing to the emerging field of critical physical geography. Future work will include interviews with forecasters from the Memphis and Nashville WFOs, leading to a more comprehensive discussion of how modes differentially affect warning and forecasting procedures across Tennessee.
Download or read book Emergency Alert System written by Maia Ruth Lee and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Disaster Resilience written by National Academies and published by National Academies Press. This book was released on 2012-12-29 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt: No person or place is immune from disasters or disaster-related losses. Infectious disease outbreaks, acts of terrorism, social unrest, or financial disasters in addition to natural hazards can all lead to large-scale consequences for the nation and its communities. Communities and the nation thus face difficult fiscal, social, cultural, and environmental choices about the best ways to ensure basic security and quality of life against hazards, deliberate attacks, and disasters. Beyond the unquantifiable costs of injury and loss of life from disasters, statistics for 2011 alone indicate economic damages from natural disasters in the United States exceeded $55 billion, with 14 events costing more than a billion dollars in damages each. One way to reduce the impacts of disasters on the nation and its communities is to invest in enhancing resilience-the ability to prepare and plan for, absorb, recover from and more successfully adapt to adverse events. Disaster Resilience: A National Imperative addresses the broad issue of increasing the nation's resilience to disasters. This book defines "national resilience", describes the state of knowledge about resilience to hazards and disasters, and frames the main issues related to increasing resilience in the United States. It also provide goals, baseline conditions, or performance metrics for national resilience and outlines additional information, data, gaps, and/or obstacles that need to be addressed to increase the nation's resilience to disasters. Additionally, the book's authoring committee makes recommendations about the necessary approaches to elevate national resilience to disasters in the United States. Enhanced resilience allows better anticipation of disasters and better planning to reduce disaster losses-rather than waiting for an event to occur and paying for it afterward. Disaster Resilience confronts the topic of how to increase the nation's resilience to disasters through a vision of the characteristics of a resilient nation in the year 2030. Increasing disaster resilience is an imperative that requires the collective will of the nation and its communities. Although disasters will continue to occur, actions that move the nation from reactive approaches to disasters to a proactive stance where communities actively engage in enhancing resilience will reduce many of the broad societal and economic burdens that disasters can cause.
Download or read book Air Force Combat Units of World War II written by Maurer Maurer and published by DIANE Publishing. This book was released on 1961 with total page 520 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Authors of the Storm written by Gary Alan Fine and published by ReadHowYouWant.com. This book was released on 2010-10-21 with total page 554 pages. Available in PDF, EPUB and Kindle. Book excerpt: Whether it is used as an icebreaker in conversation or as the subject of serious inquiry, the weather is one of the few subjects that everyone talks about. And though we recognize the faces that bring us the weather on television, how government meteorologists and forecasters go about their jobs is rarely scrutinized. Given recent weather-re...
Download or read book It s a Disaster and What Are You Gonna Do about It written by Bill Liebsch and published by . This book was released on 2001 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This information is not intended as a substitute for a first aid cvourse, but reviews some basic first aid measures that could be used when medical assistance is delayed or temporarily unavailable due to a major disaster or crisis"--Page 5
Download or read book A Failure of Initiative written by United States. Congress. House. Select Bipartisan Committee to Investigate the Preparation for and Response to Hurricane Katrina and published by . This book was released on 2006 with total page 588 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Pentagon 9 11 written by Alfred Goldberg and published by Office of the Secretary, Historical Offi. This book was released on 2007-09-05 with total page 330 pages. Available in PDF, EPUB and Kindle. Book excerpt: The most comprehensive account to date of the 9/11 attack on the Pentagon and aftermath, this volume includes unprecedented details on the impact on the Pentagon building and personnel and the scope of the rescue, recovery, and caregiving effort. It features 32 pages of photographs and more than a dozen diagrams and illustrations not previously available.
Download or read book Scanning the Skies written by Marlene Bradford and published by University of Oklahoma Press. This book was released on 2001 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt: Tornadoes, nature's most violent and unpredictable storms, descend from the clouds nearly one thousand times yearly and have claimed eighteen thousand American lives since 1880. However, the U.S. Weather Bureau--fearing public panic and believing tornadoes were too fleeting for meteorologists to predict--forbade the use of the word "tornado" in forecasts until 1938. Scanning the Skies traces the history of today's tornado warning system, a unique program that integrates federal, state, and local governments, privately controlled broadcast media, and individuals. Bradford examines the ways in which the tornado warning system has grown from meager beginnings into a program that protects millions of Americans each year. Although no tornado forecasting program existed before WWII, the needs of the military prompted the development of a severe weather warning system in tornado prone areas. Bradford traces the post-war creation of the Air Force centralized tornado forecasting program and its civilian counterpart at the Weather Bureau. Improvements in communication, especially the increasing popularity of television, allowed the Bureau to expand its warning system further. This book highlights the modern tornado watch system and explains how advancements during the latter half of the twentieth-century--such as computerized data collection and processing systems, Doppler radar, state-of-the-art television weather centers, and an extensive public education program--have resulted in the drastic reduction of tornado fatalities.
Download or read book Weekly Weather and Crop Bulletin written by and published by . This book was released on 2001 with total page 712 pages. Available in PDF, EPUB and Kindle. Book excerpt:
