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Sandy Dance, Elizabeth Ebert, and David Scurrah

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

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Patrick N. Gatlin and Steven J. Goodman

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

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Donat Perler and Oliver Marchand

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

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Alexandros A. Ntelekos, James A. Smith, and Witold F. Krajewski

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

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Tsing-Chang Chen, Ming-Cheng Yen, Jenq-Dar Tsay, Chi-Chang Liao, and Eugene S. Takle

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

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Humphrey W. Lean, Nigel M. Roberts, Peter A. Clark, and Cyril Morcrette

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

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Pin-Fang Lin, Pao-Liang Chang, Ben Jong-Dao Jou, James W. Wilson, and Rita D. Roberts

1. Introduction The primary purpose of this study is to develop a flexible algorithm based on fuzzy logic concepts to provide early assessment and prediction of afternoon thunderstorms (TS A s) in northern Taiwan. Convective weather phenomena, and especially intense thunderstorms, occupy a very important part of the Taiwan Central Weather Bureau’s (CWB) forecast and warning responsibilities. The prediction of thunderstorms (if, where, and when they will occur) is one of the most difficult tasks

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Scott M. Steiger, Richard E. Orville, and Lawrence D. Carey

1. Introduction Lightning can be used with radar observations to characterize thunderstorms and to warn people of imminent severe weather. Combined, these two datasets form a strong foundation for the short-term forecasting of convective weather. Also, relationships between radar and lightning characteristics give insight into how a thunderstorm’s dynamics and electrification processes operate. The advent of the Weather Surveillance Radar-1988 Doppler (WSR-88D) nationwide (throughout the United

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Jeffrey Frame and Paul Markowski

1. Introduction Observations have established that the extinction of the direct solar beam by the anvil clouds of supercell thunderstorms can cause significant reductions in the net radiative flux at the surface, creating low-level air temperature deficits of up to 4 K beneath the anvils of the storms ( Markowski et al. 1998 ). Dowell and Bluestein (1997) also observed a gradual 5-K temperature decrease between full sun and the onset of light precipitation in instrumented tower measurements

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Jessica R. King, Matthew D. Parker, Keith D. Sherburn, and Gary M. Lackmann

1. Introduction Severe and tornadic events in the United States predominantly occur in environments characterized by strong 0–6-km vertical wind shear and some amount of CAPE ( Schneider and Dean 2008 ). Although strong shear is generally necessary for severe convection capable of producing thunderstorms and tornadoes, CAPE varies drastically among severe environments ( Schneider et al. 2006 ; Schneider and Dean 2008 ; Grams et al. 2012 ). During the late spring and summer months, severe

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