Warning Area Research Articles

Composites of Heavy Rain Producing Elevated Thunderstorms in the Central United States

Composite analyses of the atmosphere over the central United States during elevated thunderstorms producing heavy rainfall are presented. Composites were created for five National Weather Service County Warning Areas (CWAs) in the region. Events studied occurred during the warm season (April–September) during 1979–2012. These CWAs encompass the region determined previously to experience the greatest frequency of elevated thunderstorms in the United States. Composited events produced rainfall of >50 mm 24 hr−1 within the selected CWA. Composites were generated for the 0–3 hr period prior to the heaviest rainfall, 6–9 hours prior to it, and 12–15 hours prior to it. This paper focuses on the Pleasant Hill, Missouri (EAX) composites, as all CWA results were similar; also these analyses focus on the period 0–3 hours prior to event occurrence. These findings corroborate the findings of previous authors. What is offered here that is unique is (1) a measure of the interquartile range within the composite mean fields, allowing for discrimination between variable fields that provided a strong reliable signal, from those that may appear strong but possess large variability, and (2) composite soundings of two subclasses of elevated thunderstorms. Also, a null case (one that fits the composite but failed to produce significant rainfall) is also examined for comparison.

Comparison of instability indices from COSMO-I7 and ECMWF-IFS analyses over the Piedmont Region, Italy, and new modifications to theKIndex

This paper presents a statistical analysis of heavy rain events recorded by the high resolution network of ARPA Piemonte (Piedmont Region Environmental Protection Agency) rain gauges between 2007 and 2014. In order to define convective heavy rain events over the region, a rainfall threshold of 10 mm in 20 min was chosen. Events were sampled at intervals of 6 h for the warning areas of the Piedmont Region, Italy, and their distribution was studied in relation to the values of instability indices obtained from the European Centre for Medium Range Weather Forecasts Integrated Forecasting System and the COnsortium for Small-scale MOdeling (COSMO)-I7 operational analyses. The performances of the indices of the two meteorological models were investigated for the different warning areas in a pseudo-operational weather forecasting context, obtaining useful information in the phase of issuing thunderstorm early warnings. The second part of the work had the goal of improving the performance of these indices, modifying the one that showed better verification results in terms of receiver operating characteristic (ROC) area increase and the K Index (KI). This was done by introducing dependences on the thickness of geopotential height and wind direction at different levels. KI modifications that displayed better results were called reduced K Index (KR), obtained by dividing KI by the thickness of geopotential height between 500 and 850 hPa, and KW, obtained by adjusting the KR value with additive constants depending on the wind direction at different levels. KW in particular led to a net improvement of the performance of the original KI over the region.

Safe and Environment-Friendly Forward Collision Warning Messages in the Advance Warning Area of a Construction Zone

Collisions in construction zones have always been a contributing factor in compromising safety on urban roadways. National Highway Traffic Safety Administration (NHTSA) and state transportation authorities have implemented many safety countermeasures to reduce forward collision in construction zones. However, due to the complexity of traffic in construction zones (or called work zones), traditional countermeasures often fail to prevent crashes. As such, smart warning systems could be very helpful in notifying drivers about upcoming conditions within a construction zone. In this study, a smartphone-based environment-friendly warning system was designed and its effectiveness on safety and emissions were investigated in the advance warning area of a construction zone. Four different warning messages were prepared (visual, sound, male voice and female voice) to alert drivers. Driving simulator tests with eighteen participants, driving through a construction zone for ninety rounds, were conducted to investigate the impact of smart-phone based warnings on performance measures, including headway distance, headway time, speed, deceleration, and emissions. Statistical results show that, with the help of voice (either female or male) warnings on forward collisions, acceleration rate and speed were significantly lower; and headway time and distance were significantly longer. The sound and voice warnings are beneficial to the reduction in total vehicle emissions. Moreover, participants found the notification system being user friendly and helped to avoid rear-end crashes in construction zones.

Gráficos de controle: aspectos teóricos e práticos a partir da lógica formal e da lógica fuzzy

No monitoramento de variáveis complexas, subjetivas ou mal definidas, alguns processos produtivos podem ser avaliados a partir de informações imprecisas, razão pela qual é importante buscar estratégias que viabilizem a análise e interpretação desses dados. O presente artigo apresenta uma estratégia para construção de gráficos de controle fuzzy, envolvendo também um método para transformar valores crisp em valores fuzzy e um método para ordenar números fuzzy. Os gráficos obtidos são comparados com os tradicionais gráficos de controle de Shewhart em um contexto de informações imprecisas: o estudo de algumas características sensoriais definidoras da qualidade de um produto em uma indústria de alimentos (cor, aroma, consistência, sabor e acidez). Foi constatado que os gráficos de controle fuzzy apresentaram maior flexibilidade, com a criação de zonas de alerta internas e externas, sendo menos rigorosos na avaliação da tendência central e um pouco mais rigorosos na avaliação da variabilidade, quando usado um grau de dominância maior.

Ensuring safety in human-robot coexisting environment based on two-level protection

Purpose The purpose of this paper is to provide a novel methodology based on two-level protection for ensuring safety of the moving human who enters the robot’s workspace, which is significant for dealing with the problem of human security in a human-robot coexisting environment. Design/methodology/approach In this system, anyone who enters the robot’s working space is detected by using the Kinect and their skeletons are calculated by the interval Kalman filter in real time. The first-level protection is mainly based on the prediction of the human motion, which used Gaussian mixture model and Gaussian Mixture Regression. However, even in cases where the prediction of human motion is incorrect, the system can still safeguard the human by enlarging the initial bounding volume of the human as the second-level early warning areas. Finally, an artificial potential field with some additional avoidance strategies is used to plan a path for a robot manipulator. Findings Experimental studies on the GOOGOL GRB3016 robot show that the robot manipulator can accomplish the predetermined tasks by circumventing the human, and the human does not feel dangerous. Originality/value This study presented a new framework for ensuring human security in a human-robot coexisting environment, and thus can improve the reliability of human-robot cooperation.

Modeling and simulation of voluntary employee turnover using catastrophe theory: A case study on a manufacturing enterprise in China

The Lewisian turning-point obviously increase the labor costs of Chinese manufacturing firms, it made the employee turnover to become the key problem that how to keep the enterprise human resource stability. Here, the conceptual catastrophe model of employee turnover is built from the new perspective of empirical study and catastrophe theory. In particular, we developed a parameter estimation method of the Cusp catastrophe model based on qualitative simulation and fuzzy math, and then to demonstrate the rationality and robustness of this method by a practical case on a manufacturing enterprise. In the end, a series of virtual experiments are carried out for the employee turnover in the period of China’s economic transformation. The main results are that, how to measure the warning, critical and mutation area of employee turnover; the real relationship between the complex economic environment and the demission of employees; the control policy from the macroscopic governmental measures and microscopic enterprise ways.

A Statistical Model for Regional Tornado Climate Studies.

Tornado reports are locally rare, often clustered, and of variable quality making it difficult to use them directly to describe regional tornado climatology. Here a statistical model is demonstrated that overcomes some of these difficulties and produces a smoothed regional-scale climatology of tornado occurrences. The model is applied to data aggregated at the level of counties. These data include annual population, annual tornado counts and an index of terrain roughness. The model has a term to capture the smoothed frequency relative to the state average. The model is used to examine whether terrain roughness is related to tornado frequency and whether there are differences in tornado activity by County Warning Area (CWA). A key finding is that tornado reports increase by 13% for a two-fold increase in population across Kansas after accounting for improvements in rating procedures. Independent of this relationship, tornadoes have been increasing at an annual rate of 1.9%. Another finding is the pattern of correlated residuals showing more Kansas tornadoes in a corridor of counties running roughly north to south across the west central part of the state consistent with the dryline climatology. The model is significantly improved by adding terrain roughness. The effect amounts to an 18% reduction in the number of tornadoes for every ten meter increase in elevation standard deviation. The model indicates that tornadoes are 51% more likely to occur in counties served by the CWAs of DDC and GID than elsewhere in the state. Flexibility of the model is illustrated by fitting it to data from Illinois, Mississippi, South Dakota, and Ohio.

Hail events across the Greater Metropolitan Severe Thunderstorm Warning Area

Abstract. This study addresses the recent climatology of hail occurrence in the Greater Metropolitan Severe Thunderstorm Warning Area (GMSTWA) of New South Wales (NSW). The study area is a sprawling suburban area with a population of nearly 4.7 million and one of Australia's largest metropoles. The main objective is to highlight the recent temporal–spatial fluctuations of hail event frequencies and magnitudes (sizes) for each of recognized and vastly inhabited local government areas (LGAs). The relevant hail event data from 1989 to 2013 were initially derived from the severe storm archive of the Australian Bureau of Meteorology. A climatologically oriented GIS technique was then applied in the examining and mapping procedure of all hail events and hail days reported throughout the study area. By applying a specific criterion, severe hail (defined as 2 cm or more in diameter) was cautiously selected for relevant analysis. The database includes 357 hail events with sizes 2–11 cm which occurred in 169 hail days (a day in which a hail event at least more than 2 cm reported) across the region during the past 25 years. The hail distribution patterns are neither temporally nor spatially uniform in magnitude throughout the study area. Temporal analysis indicated that most of hail events occur predominately in the afternoons with peak time of 1–5 p.m. Australian eastern standard time (EST). They are particularly common in spring and summer, reaching maximum frequency in November and December. There is an average of 14.3 events per year, but a significant decreasing trend in hail frequency and associated magnitude in the recent years has been identified. In turn, spatial analyses also established three main distribution patterns over the study area which include the Sydney metropolitan, the coastal and the most pronounced topographic effects. Based on the understanding of the favorable factors for thunderstorm development in the GMSTWA, the potential impacts from climate variability and future climate change have been briefly discussed.

Evaluation of nonlinear filtering for radar data tracking

Abstract Radar tracking plays an important role in the area of early warning and detection system, whose precision is closely connected with filtering algorithm. With the development of noise jamming technology in radar echo signal, linear filtering becomes more and more difficult to satisfy the demands of radar tracking, while nonlinear filtering can solve problems such as non-Gaussian noises. There exist a lot of nonlinear filtering algorithms at present, owning their particular characteristics. With this in mind, we provide a comprehensive overview of different nonlinear filtering algorithms in radar tracking, including basic ideas and concrete steps of them. For a more clear presentation, we also make comparisons of them from all sides. Through the analyses of different nonlinear data filters, we find that the unscented Kalman data filter (UKF) can achieve better performance than others. Therefore, we will simulate and show the performance of UKF, and performance of the extended Kalman data filter (EKF) under the same condition will be taken as comparison, whose accuracy was not ideal for radar tracking data filtering.

Verification of National Weather Service spot forecasts using surface observations

Software has been developed to evaluate National Weather Service spot forecasts. Fire management officials request spot forecasts from National Weather Service Weather Forecast Offices to provide detailed guidance as to atmospheric conditions in the vicinity of planned prescribed burns as well as wildfires that do not have incident meteorologists on site. This open source software with online display capabilities is used to examine an extensive set of spot forecasts of maximum temperature, minimum relative humidity, and maximum wind speed from April 2009 through November 2013 nationwide. The forecast values are compared to the closest available surface observations at stations installed primarily for fire weather and aviation applications. The accuracy of the spot forecasts is compared to that available from the National Digital Forecast Database (NDFD). Spot forecasts for a selected prescribed burn are used to illustrate issues associated with the verification procedures. Cumulative statistics for National Weather Service County Warning Areas and for the nation are presented. Basic error and accuracy metrics for all available spot forecasts and the entire nation indicate that the skill of the spot forecasts is higher than that available from the NDFD, with the greatest improvement for maximum temperature and the least improvement for maximum wind speed.

A new methodology to assess the benefits of flood warning

AbstractA new assessment methodology is presented for the benefits of flood warning that applies both tangible and intangible benefits from warning generation and dissemination using a multi‐criteria analysis (MCA). The resulting decision support tool allows benefits to be scored transparently, reinforced by Geographical Information System (GIS) procedures. A wide range of benefits are scored including: protection of key infrastructure, avoided social impacts, timely operation of flood defences and avoided risks to life from the flood hazard. Pilot testing on some 22 sites at a variety of scales (catchments and flood warning areas) showed that the method works effectively when making ‘like for like’ comparisons, considering a wholly new system for large catchments, or upgrades to warning and dissemination systems in sub‐catchment flood warning areas. The methodology promotes consultation and data interchange between the warning organisation and end‐users in order to prioritise particular areas of need for new or improved systems.

One year after the June 2010 events in Kyrgyzstan: the possible implications for regional security

AbstractThis article includes some ideas on the crisis that took place in Osh, Kyrgyzstan in June 2010. Apart from a brief summary of the events, it describes viewpoints of the main 'actors' including the international organizations; it also seeks an answer to the question on what the reasons leading up to these tragic events were. Regarding possible sources of conflicts, including the factor of ethnic minorities, the question arises whether the various international mechanisms created for handling regional conflicts function properly, in a conducive way, and whether they can warn the international community of an evolving crisis and prevent conflicts. According to the facts, in the concrete case of the Osh crisis, the OSCE High Commissioner on National Minorities succeeded in fulfilling his task in the area of early warning; however, no concrete actions were taken by the above-mentioned 'actors' in regional and international politics to prevent the conflict. This paper has no intention of dwelling on this issue as it was very adequately addressed by an earlier article written by Sabine Machl. The ethnic conflicts of 1990 and 2010 in Central Asia demonstrate the vulnerability of the region, which also faces some additional challenges in the field of security. This article does not intend to examine all the aspects of the Kyrgyz crisis. However, as some experts at the time of the Osh events explicitly mentioned, the possibility of the infiltration of militants from Afghanistan and their involvement in the clashes and as Afghanistan itself is a country, where about half of the population belong to various ethnic 'minority' groups (Tajiks, Uzbeks, Hazaras, Turkmens, etc.), one cannot ignore the danger of the implication of the conflict going on in Afghanistan for its vicinity, including Central Asia. The awareness of this challenge was reflected in various ideas and suggestions (to address the Afghan crisis) emanating from these countries. The most comprehensive of these — according to the views of the author of this article — is the so called '6+3' initiative developed by Uzbekistan. One of the 'messages' of this article should be that, at the present, stronger and more consistent as well as concerted efforts are needed to deal with evolving conflicts and crises in the broader region of Central and West Asia, where these potential conflicts may develop not only by themselves, in separate countries or 'sub-regions', but they could include the danger of a 'spillover' which may also effect other countries.

Experimental Assessment of the RESCUE Collision-Mitigation System

Road-traffic-incident analysis has shown that 52% of incidents are caused by a collision between two vehicles or between a vehicle and an obstacle. In this paper, the REduce Speed of Collision Under Emergency (RESCUE) collision-mitigation system (version 1.0) is presented and evaluated toward various typical road situations. The aim of the RESCUE system is to decrease the kinetic energy dissipated during a collision through automatic emergency braking that occurs 1 s before the collision. This emergency braking is triggered by an alarm coming from a decision unit taking into consideration the results of a generic obstacle-detection system-based on fusion between stereovision and laser scanner-and a warning area in front of the vehicle. The different subsystems are presented. Then, the behavior of the RESCUE collision-mitigation system toward various typical dangerous road situations is assessed through systematic tests. These quantitative tests are completed by qualitative ones carried out on 737 km of open roads (freeways, highways, rural roads, downtown) to provide a more precise idea about the false-alarm rate. The experiments show the system is promising in terms of reliability, genericity, and efficiency

The Evolution of Morning Convective Systems over the U.S. Great Plains during the Warm Season. Part I: The Forecast Problem

The factors that influence the evolution of convective systems during the late morning over much of the Great Plains are not understood well. It is known that in this region the majority of such systems dissipate or decrease in intensity during this period. With this fact in mind, a summary is given of comments made during the occurrence of morning convective systems by forecasters at two National Weather Service (NWS) offices relating to factors that were most important in determining their forecasts of system evolution. In addition, results of a preliminary climatological study covering eight summer months for 181 summer precipitation systems affecting the county warning areas of the two NWS offices during late morning are presented. Revealed among the significant system characteristics is that approximately two-thirds of the included systems either decreased in intensity or dissipated during the late morning.

Attribution-related causes of a difficult doctor-patient relationship

Network-wide traffic control strategies (e.g. perimeter control and route guidance) in urban networks have recently been mainly studied to relieve or postpone congestion based on the theory of macroscopic fundamental diagram (MFD). Nevertheless, these studies are mostly applied to the statically partitioned networks or the dynamic networks that fail to fully consider traffic state prediction, conflicting with strongly spatiotemporal variability of traffic congestion or objective of active traffic management (ATM). This paper proposes a methodology to dynamically identify critical congestion warning areas from heterogeneous urban road networks, which aids to design efficient perimeter control approaches. In the methodology, a dynamic directed weighted network is built on the base of the link connectivity and the real-time traffic loads, and a link travel time prediction method based on Kalman filter is developed to calibrate directed weight values and undirected input values for links. With the undirected link input information, a dynamic congestion warning community detection method which consists of three consecutive steps is developed. Firstly, it could capture emergence of new congestion areas based on the definition of congestion seed intersection. Secondly, expansion and regression of each congested area could be achieved with the objectives of spatial compactness and traffic condition homogeneity. Thirdly, a two-level merging algorithm of adjacent different congestion areas is designed utilizing modularity model in community detection of complex networks. The proposed methodology is validated using ground truth data from downtown network of Jinan City in China. The results show that the proposed algorithms can efficiently track congestion evolutionary processes and effectively detect congestion warning areas from the test real network.

Selected Efforts/Research in the Area of Early Warning

Selected Efforts/Research in the Area of Early Warning

Active Man Machine Interface for Advanced Rotorcraft

The proliferation of digital avionic information presented to pilots has produced a critical need for intelligent avionic information management, particularly in the area of Caution, Warning, and Advisory (CWA) systems. This demonstration illustrates the role of an Active Man Machine Interface (AMMI) in the context of CWA systems in rotorcraft of the future. The basis of the AMMI's intelligence demonstrated here is provided by a cognitive model that 1) prunes the alert stream to only those messages that have meaning to the pilot depending on the tactical context, and 2) provide context-sensitive advice on the basis of the tactical context. The CWA AMMI is currently being designed using COGNET, an cognitive modelling methodology (Zachary, 1989), and implemented using BATON, a set of software tools used to implement and embed COGNET models into existing systems (Zachary et al, 1991).

Characteristics of East-Central Florida Tornado Environments

Abstract Climatological analyses indicate that strong morning tornadoes in the dry season, and weak afternoon tornadoes in the wet season, are significant forecast problems in east-central Florida. To address this issue, an analysis of upper-air soundings for Tampa Bay, West Palm Beach, and Cape Canaveral, Florida, released within ±2 hours of tornado touchdowns in the County Warning Area (CWA) of future National Weather Service (NWS) Weather Forecast Office (WFO), Melbourne, Florida, was completed. Mean dry- and wet-season tornado-proximity soundings to 200 mb were produced, and selected mean diagnostic parameters and variance statistics computed. Both dry- and wet-season tornado environments were associated with deep moist layers overlain by dry air, but no capping inversions. Dry-season cases were characterized by lower-tropospheric ow values well above normal, very low Convective Available Potential Energy (CAPE) and Bulk Richardson Number (BRN), strong speed and directional shear at low levels, a stro...