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1. Introduction Providing public warnings of impending thunderstorms is an important role of weather services. By observing the motion and evolution of thunderstorms using radar data, forecasters can reasonably predict the location and severity of thunderstorms up to 1 h into the future. This is an example of what is widely known as “nowcasting.” To help objectify and automate the nowcasting process, many radar-based systems have been developed in recent years. Among these are Thunderstorm
1. Introduction Providing public warnings of impending thunderstorms is an important role of weather services. By observing the motion and evolution of thunderstorms using radar data, forecasters can reasonably predict the location and severity of thunderstorms up to 1 h into the future. This is an example of what is widely known as “nowcasting.” To help objectify and automate the nowcasting process, many radar-based systems have been developed in recent years. Among these are Thunderstorm
DECEMBER 1948 HORACE R. BYERS AND HARRIET R. RODEBUSH275CAUSES OF THUNDERSTORMS OF THE FLORIDA PENINSULABy Horace R. Dyers and Harriet R. Rodebush U. S. Weather Bureau Thunderstorm Project and the University of Chicago' (Manuscript received 5 May 1948)ABSTRACTAfter a study of temperature and humidity soundings in Florida during the summer of 1946 failed toproduce an explanation for the occurrence or nonoccurrence of thunderstorms, the theory was proposed thatlarge
DECEMBER 1948 HORACE R. BYERS AND HARRIET R. RODEBUSH275CAUSES OF THUNDERSTORMS OF THE FLORIDA PENINSULABy Horace R. Dyers and Harriet R. Rodebush U. S. Weather Bureau Thunderstorm Project and the University of Chicago' (Manuscript received 5 May 1948)ABSTRACTAfter a study of temperature and humidity soundings in Florida during the summer of 1946 failed toproduce an explanation for the occurrence or nonoccurrence of thunderstorms, the theory was proposed thatlarge
1. Introduction The purpose of this study is to examine the utility of using trends in total lightning activity to help diagnose the severe weather potential of a thunderstorm. An algorithm derived from total lightning data measurements (both cloud and ground flashes) has been developed to help gauge thunderstorm intensity. This algorithm attempts to predict severe weather without the use of any radar observables. The proposed total lightning algorithm is based upon the observations of rapid
1. Introduction The purpose of this study is to examine the utility of using trends in total lightning activity to help diagnose the severe weather potential of a thunderstorm. An algorithm derived from total lightning data measurements (both cloud and ground flashes) has been developed to help gauge thunderstorm intensity. This algorithm attempts to predict severe weather without the use of any radar observables. The proposed total lightning algorithm is based upon the observations of rapid
1. Introduction This study investigates adaptive boosting, a relatively new classification method introduced by Freund and Schapire (1997) , to numerical weather prediction (NWP) output postprocessing. As a case study, we show how this machine learning method can be used to detect thunderstorms in NWP forecast output fields. NWP uses the basic physical equations of the atmosphere for simulation. Predicting thunderstorms with NWP models is inherently difficult. This is because of the rather
1. Introduction This study investigates adaptive boosting, a relatively new classification method introduced by Freund and Schapire (1997) , to numerical weather prediction (NWP) output postprocessing. As a case study, we show how this machine learning method can be used to detect thunderstorms in NWP forecast output fields. NWP uses the basic physical equations of the atmosphere for simulation. Predicting thunderstorms with NWP models is inherently difficult. This is because of the rather
1. Introduction Flash flooding in urban drainage basins is an increasingly important hazard in terms of loss of life and property damage (i.e., Carpenter et al. 1999 ; Smith et al. 2002 ; Ogden et al. 2000 ). In this paper we examine the linkage between organized thunderstorm systems and flash floods in urban drainage basins through analyses of cloud-to-ground (CG) lightning observations and discharge data from the Baltimore, Maryland, metropolitan region. The questions that motivate this
1. Introduction Flash flooding in urban drainage basins is an increasingly important hazard in terms of loss of life and property damage (i.e., Carpenter et al. 1999 ; Smith et al. 2002 ; Ogden et al. 2000 ). In this paper we examine the linkage between organized thunderstorm systems and flash floods in urban drainage basins through analyses of cloud-to-ground (CG) lightning observations and discharge data from the Baltimore, Maryland, metropolitan region. The questions that motivate this
1. Introduction The air quality, municipal water supply, and air and land traffic hazards for three million people in the Taipei basin of Taiwan during the summer season are strongly influenced by thunderstorms and their unique interaction with the land–sea-breeze circulation. Formed by the intersection of the Tanshui and Keelung River valleys, the Taipei basin is located in northern Taiwan, surrounded by mountains in three directions (north, southwest, and southeast), and is connected to the
1. Introduction The air quality, municipal water supply, and air and land traffic hazards for three million people in the Taipei basin of Taiwan during the summer season are strongly influenced by thunderstorms and their unique interaction with the land–sea-breeze circulation. Formed by the intersection of the Tanshui and Keelung River valleys, the Taipei basin is located in northern Taiwan, surrounded by mountains in three directions (north, southwest, and southeast), and is connected to the
Balloons ascending simultaneously at various points around thunderstorms are followed by radar or radio-direction finding (rawins and rawinsondes) to determine horizontal inflow or outflow of the air. It is found that in the early stages of development of a thunderstorm cell, inflow or horizontal convergence is present at the ground as well as all heights reached by the cloud. In a mature thunderstorm cell, the observations show outflow or horizontal divergence under the cloud base and convergence at all heights between about 4,000 and 23,000 feet, with divergence again in the uppermost levels. Relationships to rainfall and to cloud entrainment of environmental air are shown.
Balloons ascending simultaneously at various points around thunderstorms are followed by radar or radio-direction finding (rawins and rawinsondes) to determine horizontal inflow or outflow of the air. It is found that in the early stages of development of a thunderstorm cell, inflow or horizontal convergence is present at the ground as well as all heights reached by the cloud. In a mature thunderstorm cell, the observations show outflow or horizontal divergence under the cloud base and convergence at all heights between about 4,000 and 23,000 feet, with divergence again in the uppermost levels. Relationships to rainfall and to cloud entrainment of environmental air are shown.
fatalities have been attributed to hazardous weather conditions (lightning, hail, heavy rain, and thunderstorm outflows) from the frequent occurrence of nocturnal thunderstorms. Lake Victoria thunderstorms are well known as one of the lightning hotspots on Earth ( Zipser et al. 2006 ; Albrecht et al. 2016 ), with extreme danger to human life. This paper is based on data from a polarimetric Doppler radar located in Mwanza, Tanzania, along the south shore of Lake Victoria. The data were available from
fatalities have been attributed to hazardous weather conditions (lightning, hail, heavy rain, and thunderstorm outflows) from the frequent occurrence of nocturnal thunderstorms. Lake Victoria thunderstorms are well known as one of the lightning hotspots on Earth ( Zipser et al. 2006 ; Albrecht et al. 2016 ), with extreme danger to human life. This paper is based on data from a polarimetric Doppler radar located in Mwanza, Tanzania, along the south shore of Lake Victoria. The data were available from
by Morcrette et al. (2007 , hereafter M07) . We present a series of model experiments designed to elucidate the processes that came together to cause the initiation of an isolated thunderstorm over southern England. Section 2 presents an overview of the case and further motivates the work. Section 3 describes the model and its configuration used in this study. Section 4 discusses the origin of the convergence line inferred by M07 as contributing to the initiation of the shower. Section
by Morcrette et al. (2007 , hereafter M07) . We present a series of model experiments designed to elucidate the processes that came together to cause the initiation of an isolated thunderstorm over southern England. Section 2 presents an overview of the case and further motivates the work. Section 3 describes the model and its configuration used in this study. Section 4 discusses the origin of the convergence line inferred by M07 as contributing to the initiation of the shower. Section
), as well as terrestrial water storage variations ( Deng et al. 2018 ). The rapid expansion and outburst floods of glacial lakes and snow and ice avalanches on the TP are also becoming frequent ( Richardson and Reynolds 2000 ; Wang et al. 2015 ; Tian et al. 2017 ). As discussed above, previous studies primarily focused on changes in temperature, water vapor, and precipitation on the TP. There were few investigations in distributions and changes of thunderstorm, hail, gale, and heavy precipitation
), as well as terrestrial water storage variations ( Deng et al. 2018 ). The rapid expansion and outburst floods of glacial lakes and snow and ice avalanches on the TP are also becoming frequent ( Richardson and Reynolds 2000 ; Wang et al. 2015 ; Tian et al. 2017 ). As discussed above, previous studies primarily focused on changes in temperature, water vapor, and precipitation on the TP. There were few investigations in distributions and changes of thunderstorm, hail, gale, and heavy precipitation
