Multidisciplinary Analysis of an Unusual Tornado: Meteorology, Climatology, and the Communication and Interpretation of Warnings*

2010 ◽  
Vol 25 (5) ◽  
pp. 1412-1429 ◽  
Author(s):  
Russ S. Schumacher ◽  
Daniel T. Lindsey ◽  
Andrea B. Schumacher ◽  
Jeff Braun ◽  
Steven D. Miller ◽  
...  
Keyword(s):  
Time Of Day ◽  
Severe Weather ◽  
Decision Makers ◽  
Future Research ◽  
Front Range ◽  
National Weather Service ◽  
Weather Information ◽  
Multidisciplinary Analysis ◽  
Local Decision ◽  
Weather Service

Abstract On 22 May 2008, a strong tornado—rated EF3 on the enhanced Fujita scale, with winds estimated between 136 and 165 mi h−1 (61 and 74 m s−1)—caused extensive damage along a 55-km track through northern Colorado. The worst devastation occurred in and around the town of Windsor, and in total there was one fatality, numerous injuries, and hundreds of homes significantly damaged or destroyed. Several characteristics of this tornado were unusual for the region from a climatological perspective, including its intensity, its long track, its direction of motion, and the time of day when it formed. These unusual aspects and the high impact of this tornado also raised a number of questions about the communication and interpretation of information from National Weather Service watches and warnings by decision makers and the public. First, the study examines the meteorological circumstances responsible for producing such an outlier to the regional severe weather climatology. An analysis of the synoptic and mesoscale environmental conditions that were favorable for significant tornadoes on 22 May 2008 is presented. Then, a climatology of significant tornadoes (defined as those rated F2 or higher on the Fujita scale, or EF2 or higher on the Enhanced Fujita scale) near the Front Range is shown to put the 22 May 2008 event into climatological context. This study also examines the communication and interpretation of severe weather information in an area that experiences tornadoes regularly but is relatively unaccustomed to significant tornadoes. By conducting interviews with local decision makers, the authors have compiled and chronicled the flow of information as the event unfolded. The results of these interviews demonstrate that the initial sources of warning information varied widely. Decision makers’ interpretations of the warnings also varied, which led to different perceptions on the timeliness and clarity of the warning information. The decision makers’ previous knowledge of the typical local characteristics of tornadoes also affected their interpretations of the tornado threat. The interview results highlight the complex series of processes by which severe weather information is communicated after a warning is issued by the National Weather Service. The results of this study support the growing recognition that societal factors are just as important to the effectiveness of weather warnings as the timeliness of and information provided in those warnings, and that these factors should be considered in future research in addition to the investments and attention given to improving detection and warning capabilities.

scholarly journals Impacts as Triggers for Weather-Related Decision Making: Observations at the Berlin Fire Brigade Control and Dispatch Center

2021 ◽  
Author(s):  
Thomas Kox ◽  
Catharina Lüder
Keyword(s):  
Decision Making ◽  
Ad Hoc ◽  
Emergency Services ◽  
Ground Truth ◽  
Severe Weather ◽  
Personal Contact ◽  
Technical Equipment ◽  
Fire Brigade ◽  
Weather Information ◽  
Weather Service

AbstractThis article presents the results of a series of ethnographic observations at the Berlin fire brigade control and dispatch center during routine and severe weather situations. The weather-related challenges of a fire brigade lie between the anticipation of events and their potential consequences, and the ad hoc reactions to actual impacts of weather. The results show that decisions and actions related to high impact weather are not necessarily motivated by weather warnings alone. Instead, they are reactions to the experience of impacts, for example, an increased number of missions or emergency calls. Impacts are the main trigger for the decision making. Weather is one additional external factor that influences the operational capability of a fire brigade. While commanding officers in a fire brigade control and dispatch center experience weather primarily through technical equipment, verified by ground truth, observations showed that direct personal contact with the regional weather service and colleagues on the ground takes on a greater role in actual severe weather situations. The observations point to the need for increased interagency communication between the emergency services, the weather service, and other organizations to integrate weather information, impacts, and non-weather-related tasks into coherent weather-related decision making.

scholarly journals By the Numbers: DAP: Digital Analytics Program

2016 ◽  
Vol 44 (1) ◽  
pp. 7
Author(s):  
Pamela Campbell
Keyword(s):  
Federal Agencies ◽  
Decision Makers ◽  
National Library ◽  
National Weather Service ◽  
Good Data ◽  
The Us ◽  
Government Websites ◽  
Weather Service ◽  
General Services Administration

Every day, millions of people access government websites. Over the thirty days preceding the date this article was written, the National Weather Service and the National Library of Medicine each received more than 50 million visits. According to the US General Services Administration, there are over 1,300 dot-gov domains in use by federal agencies. Given the immense resources involved in building and maintaining these websites, sound decisions about allocating these resources are important. And that means decision makers need good data.

scholarly journals Usefulness of the United States National Weather Service Radar Display as Rated by Website Users

2018 ◽  
Vol 10 (4) ◽  
pp. 673-691 ◽  
Author(s):  
Michelle E. Saunders ◽  
Kevin D. Ash ◽  
Jennifer M. Collins
Keyword(s):  
United States ◽  
Spatial Clustering ◽  
Weather Radar ◽  
Weather Conditions ◽  
Radar Data ◽  
The United States ◽  
Perceived Usefulness ◽  
National Weather Service ◽  
Weather Information ◽  
Weather Service

Abstract Weather radar is now widely viewed by the general public in the United States via television, computers/tablets, and smartphones. Anyone can consult near-real-time maps and animations of weather radar data when weather conditions are a factor. However, the usefulness of weather radar data for each user depends on a complex interaction of factors. There have been few studies providing conceptual arguments and empirical data to better understand what the most important factors are and to comprehend patterns of public weather radar use across the United States. The first part of this research provides a basic conceptual framework for research investigating the usefulness of weather radar displays as a source of weather information and as a decision aid. The second part aims to uncover several factors that influence the perceived usefulness rating of the National Weather Service (NWS) website’s weather radar display at both national and regional levels using variables gathered from the 2014 NWS customer satisfaction survey alongside relevant geographic and climatological variables. Data analyses include spatial clustering and ordinal regression utilized within a generalized linear model methodology. Overall, respondents who are more familiar with the NWS and their products, as well as those who indicate they are more likely to take action based on information provided by the NWS, are more likely to find the NWS radar display useful. Geographically, the NWS radar display is most useful to persons residing in the southern United States. Lightning is the most important hazard associated with higher radar usefulness ratings.

An Hourly Climatology of Operational MRMS MESH-Diagnosed Severe and Significant Hail with Comparisons to Storm Data Hail Reports

2021 ◽  
Author(s):  
Nathan A. Wendt ◽  
Israel L. Jirak
Keyword(s):  
Population Density ◽  
Real Time ◽  
Risk Information ◽  
Severe Weather ◽  
Radar Reflectivity ◽  
Real Time Monitoring ◽  
National Weather Service ◽  
Convective Weather ◽  
The Relationship ◽  
Weather Service

AbstractThe multi-radar/multi-sensor (MRMS) system generates an operational suite of derived products in the NationalWeather Service useful for real-time monitoring of severe convective weather. One such product generated byMRMSis the maximum estimated size of hail (MESH) that estimates hail size based on the radar reflectivity properties of a storm above the environmental 0 °C level. The MRMS MESH product is commonly used across the National Weather Service (NWS), including the Storm Prediction Center (SPC), to diagnose the expected hail size in thunderstorms. Previous work has explored the relationship between the MRMS MESH product and severe hail (≥ 25.4 mm or 1 in.) reported at the ground. This work provides an hourly climatology of severe MRMS MESH across the contiguous U.S. from 2012–2019, including an analysis of how the MESH climatology differs from the severe hail reports climatology. Results suggest that the MESH can provide beneficial hail risk information in areas where population density is low. Evidence shows that the MESH can provide potentially beneficial information about severe hail occurrence during the night in locations that are climatologically favored for upscale convective growth and elevated convection. These findings have important implications for the use of MESH as a verification dataset for SPC probabilistic hail forecasts as well as severe weather watch decisions in areas of higher hail risk but low population density.

scholarly journals Severe Weather Warnings: impact of an event vs. impact of a warning.

2021 ◽  
Author(s):  
Saskia Willemse ◽  
Nathalie Popovic ◽  
Nikolina Fuduric ◽  
Léonie Bisang ◽  
Cécile Zachlod
Keyword(s):  
Design Thinking ◽  
Extreme Event ◽  
Governance Structure ◽  
Extreme Weather ◽  
Severe Weather ◽  
Extreme Weather Events ◽  
National Weather Service ◽  
Key Accounts ◽  
The Impact ◽  
Weather Service

<p>The most important question a national weather service should ask itself in connection with its warning task is: "Do our warnings contribute to reducing the impact of extreme weather events?". A perfect impact forecast of an extreme weather event does not necessarily contribute to reduce the impact of the event. Even the most perfect warning, whether based on physical thresholds or on potential impact, is not a guarantee for a reduction of the impact of the warned extreme event. Only If the warning reaches the recipient in time, is understood and action is taken, is there a chance that the impact can be reduced, which means that the warning unfolds an impact. Therefore, if we want the recipient to understand the warnings and to know what action to take, we have to know what his needs are.</p><p>In this contribution we describe a method (“Jobs to be done”) with which we investigated the needs of the authorities in terms of severe weather warnings in Switzerland and we will present the results of this investigation. This method focuses our attention on those processes that are important to the authorities but unsatisfactorily fulfilled. Once isolated, we engage our experts in cooperation with the authorities to find optimal and innovative solutions through design thinking workshops. In the Swiss federal structure, the warning chain extends over all levels of the governance structure: the severe weather warnings are issued at federal level and transmitted to the Cantons, these can decide to add local information, particularly concerning impact, and transmit them to the communities and the population. In our investigation, we concentrated on the administrative authorities and on the cantonal coordination bodies of the fire brigades. The aim of this study is to find indications for optimising the warnings, in terms of content, representation and also distribution.</p><p>The investigation started in January 2021 with a series of interviews with seven natural hazard experts and six fire inspectors of different Cantons. Currently (April 2021) we are running two surveys in all Cantons and in June we plan two workshops with representatives of the Cantons and of the fire brigades together with collaborators of the National Weather Service MeteoSwiss (forecasters, developers and key accounts). </p>

An Analysis of 2016-2018 Tornadoes and National Weather Service Tornado Warnings across the contiguous United States

2021 ◽  
Author(s):  
Evan S. Bentley ◽  
Richard L. Thompson ◽  
Barry R. Bowers ◽  
Justin G. Gibbs ◽  
Steven E. Nelson
Keyword(s):  
United States ◽  
Rotational Velocity ◽  
Radar Data ◽  
Probability Of Detection ◽  
False Alarms ◽  
National Weather Service ◽  
Low Level ◽  
Tornado Warnings ◽  
Tornado Warning ◽  
Weather Service

AbstractPrevious work has considered tornado occurrence with respect to radar data, both WSR-88D and mobile research radars, and a few studies have examined techniques to potentially improve tornado warning performance. To date, though, there has been little work focusing on systematic, large-sample evaluation of National Weather Service (NWS) tornado warnings with respect to radar-observable quantities and the near-storm environment. In this work, three full years (2016–2018) of NWS tornado warnings across the contiguous United States were examined, in conjunction with supporting data in the few minutes preceding warning issuance, or tornado formation in the case of missed events. The investigation herein examines WSR-88D and Storm Prediction Center (SPC) mesoanalysis data associated with these tornado warnings with comparisons made to the current Warning Decision Training Division (WDTD) guidance.Combining low-level rotational velocity and the significant tornado parameter (STP), as used in prior work, shows promise as a means to estimate tornado warning performance, as well as relative changes in performance as criteria thresholds vary. For example, low-level rotational velocity peaking in excess of 30 kt (15 m s−1), in a near-storm environment which is not prohibitive for tornadoes (STP > 0), results in an increased probability of detection and reduced false alarms compared to observed NWS tornado warning metrics. Tornado warning false alarms can also be reduced through limiting warnings with weak (<30 kt), broad (>1nm) circulations in a poor (STP=0) environment, careful elimination of velocity data artifacts like sidelobe contamination, and through greater scrutiny of human-based tornado reports in otherwise questionable scenarios.

scholarly journals Long-Term Performance Metrics for National Weather Service Tornado Warnings

2018 ◽  
Vol 33 (6) ◽  
pp. 1501-1511 ◽  
Author(s):  
Harold E. Brooks ◽  
James Correia
Keyword(s):  
False Alarm ◽  
Lead Time ◽  
Performance Metrics ◽  
Warning System ◽  
Probability Of Detection ◽  
False Alarms ◽  
National Weather Service ◽  
False Alarm Ratio ◽  
Tornado Warnings ◽  
Weather Service

Abstract Tornado warnings are one of the flagship products of the National Weather Service. We update the time series of various metrics of performance in order to provide baselines over the 1986–2016 period for lead time, probability of detection, false alarm ratio, and warning duration. We have used metrics (mean lead time for tornadoes warned in advance, fraction of tornadoes warned in advance) that work in a consistent way across the official changes in policy for warning issuance, as well as across points in time when unofficial changes took place. The mean lead time for tornadoes warned in advance was relatively constant from 1986 to 2011, while the fraction of tornadoes warned in advance increased through about 2006, and the false alarm ratio slowly decreased. The largest changes in performance take place in 2012 when the default warning duration decreased, and there is an apparent increased emphasis on reducing false alarms. As a result, the lead time, probability of detection, and false alarm ratio all decrease in 2012. Our analysis is based, in large part, on signal detection theory, which separates the quality of the warning system from the threshold for issuing warnings. Threshold changes lead to trade-offs between false alarms and missed detections. Such changes provide further evidence for changes in what the warning system as a whole considers important, as well as highlighting the limitations of measuring performance by looking at metrics independently.

scholarly journals International and regional variation in the prevalence of common mental disorders: do we need more surveys?

2004 ◽  
Vol 184 (4) ◽  
pp. 289-290 ◽  
Author(s):  
Scott Weich ◽  
Ricardo Araya
Keyword(s):  
Mental Disorders ◽  
Regional Variation ◽  
Common Mental Disorders ◽  
Psychiatric Morbidity ◽  
Epidemiological Survey ◽  
Decision Makers ◽  
Local Decision ◽  
Local Decision Makers ◽  
Geographical Locations

Vicente and his colleagues present admirably concise findings from a large epidemiological survey of non-psychotic psychiatric morbidity in four different geographical locations in Chile (Vicente et al, 2004, this issue). Without gainsaying the importance of psychiatric morbidity in that country, many readers, including local decision-makers, may find it difficult to assimilate these results.

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