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John Molinari, David M. Romps, David Vollaro, and Leon Nguyen

to 300 km the maximum shifted to downshear right. Abarca et al. (2011) updated these results using a long-range network that sampled storms over open ocean as well as near land. The vast majority of electrified convection outside the 100-km radius occurred downshear or downshear right. Molinari and Vollaro (2010) showed that convective available potential energy (CAPE) averaged from 75- to 400-km radii was 60% larger downshear than upshear. They hypothesized that the larger CAPE arose from

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David M. Romps

1. Introduction Convective available potential energy (CAPE), which is a function of the atmosphere’s temperature profile and near-surface humidity, is the maximum specific vertical kinetic energy w 2 /2 that storm clouds can theoretically attain while rising. CAPE plays a critical role in the prediction of severe weather ( Johns and Doswell III 1992 ; Brooks et al. 1994 ; Rasmussen and Blanchard 1998 ; Rasmussen 2003 ; Brooks et al. 2003 ) and lightning ( Williams et al. 1992 , 2002

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Reinhold Steinacker

. Since then, it was realized that cyclogenesis in the extratropics needs a certain amount of initial baroclinicity. The application of parcel theory for convective processes in the atmosphere led to the formulation of the convective available potential energy (CAPE; Moncrieff and Miller 1976 ). It is interesting to note that Margules (1905) also treated a case with a vertical rearrangement of air volumes but came to the conclusion that (dry) unstable stratification is rarely observed in the

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David K. Adams and Enio P. Souza

1. Introduction Understanding the relationship between the energy available for atmospheric convection and convective activity has engendered a great deal of research in the atmospheric sciences. One common measure of convective energy used in many studies is the convective available potential energy (CAPE), the vertically integrated parcel buoyant energy ( Moncrieff and Miller 1976 ). CAPE is most frequently used as a forecasting tool for gauging severe thunderstorm likelihood since it

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Vince Agard and Kerry Emanuel

spatial extent is too small for them to be resolved by general circulation models. This difficulty is exacerbated in continental convective environments, where, unlike for oceanic convection, the atmosphere cannot be considered to be in radiative–convective equilibrium. Therefore, climate research on these severe local storms often focuses on the environments in which severe local storms are formed. Convective available potential energy (CAPE) and deep-layer vertical wind shear are two important

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Callyn Bloch, Robert O. Knuteson, Antonia Gambacorta, Nicholas R. Nalli, Jessica Gartzke, and Lihang Zhou

potential energy (CAPE) is a well-established measure of buoyancy-driven atmospheric instability that is computed from vertical profiles of temperature and water vapor ( Blanchard 1998 ; Doswell and Rasmussen 1994 ; Holley et al. 2014 ). CAPE is important in forecasting severe weather, and is also used to derive other severe weather parameters including the bulk Richardson number (BRN), the significant tornado parameter (STP), and the supercell composite parameter (SCP). ( Bunkers et al. 2002

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Torsten Linders and Øyvind Saetra

1. Introduction Conditional instability has been called upon to explain different types of atmospheric cyclonic activity, at least since the 1940s. McDonald (1942) reports on radio soundings in August 1940 from Swan Island in the Caribbean that “tremendous amounts of energy were potentially available in a state of conditional instability.” The concept of convective available potential energy (CAPE) has been used as one measure of how favorable the atmospheric state is to the formation of

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J. Cody Kirkpatrick, Eugene W. McCaul Jr., and Charles Cohen

helicity (SRH), and low-level absolute humidity is important for sustaining “long-lived” supercells ( Brooks et al. 1994 ). Midtropospheric humidity can significantly affect simulated storm morphology ( Gilmore and Wicker 1998 ), having implications for storm motions. The results presented in MW01 and MC02 highlight the need to consider additional atmospheric variables, beyond simple measures of bulk CAPE and vertical wind shear, to fully explain the evolution of discrete, isolated convective

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JUNE 1960 MONTHLY W E A T H E R R E V I E W 223SOIL TEMPERATURESAT CAPE HALLETT, ANTARCTICA, 1958NORMAN S. BENESU.S. Weather Bureau, Phoenix, Ariz. *[Manuscript received April 11, 1960; revised June 27, 19601ABSTRACTSoil temperatures at 10- and 50-cm. levels were obtained a t Cape Hallett from April through December 1958.The instrumentation used is described and graphs and tables of the results obtained are presented.1. INTRODUCTIONHallett is one of the few Antarctic stations not locatedon a

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Ron McTaggart-Cowan, Paul A. Vaillancourt, Leo Separovic, Shawn Corvec, and Ayrton Zadra

employ schemes that relate the deep convective activity directly to the convective available potential energy (CAPE) of the near-storm environment ( Yano et al. 2013 ). In contrast, the topic of representing convection in environments with limited conditional instability (low CAPE) has received relatively little attention. However, accurately depicting such events is shown here to have the potential to impact the quality of the model solution significantly. The potential for vigorous moist convection

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