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Richard E. Orville, Gary R. Huffines, William R. Burrows, and Kenneth L. Cummins

1. Introduction Lightning incidence throughout northern Mexico, the continental United States, Canada, Alaska, and nearby coastal waters is currently observed by the North American Lightning Detection Network (NALDN). This network is operated as a seamless integration of the Canadian Lightning Detection Network (CLDN) and the U.S. National Lightning Detection Network (NLDN). Our summaries of annual lightning flash characteristics for the continental United States began in 1989 ( Orville 1991

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XiaoJing Jia, Hai Lin, and Jacques Derome

1. Introduction It is well known that some teleconnection patterns, such as the Pacific–North American (PNA) pattern and the North Atlantic Oscillation (NAO), can significantly influence the seasonal atmospheric conditions over North America ( Wallace and Guztler 1981 ; Barnston and Livezey 1987 ). The external forcing associated with sea surface temperature (SST) anomalies is known to play an important role in the variability of the PNA, and to a lesser extent of the NAO ( Horel and Wallace

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David K. Adams and Enio P. Souza

observed ( Sherwood 1999 ; Tompkins 2001 ; Sobel et al. 2004 ). These studies also highlight what seems to be a regional or regime-dependent relationship between large-scale forcing, the local thermodynamic environment, and the phase relationship between instability and convective activity. In this study, we investigate the nature of the CAPE–precipitation relationship for the convective regime along the periphery of the North American monsoon (NAM). The motivations for this study lie in

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Zachary O. Finch and Richard H. Johnson

1. Introduction The North American monsoon (NAM) is an important and complex atmospheric circulation that results in a pronounced increase in rainfall from a dry June to a rainy July over the southwestern United States and northwestern Mexico ( Adams and Comrie 1997 ). Douglas et al. (1993) show that western Mexico receives 60%–70% of annual precipitation during the 3-month period from July to September. The dramatic increase in rainfall is accompanied by a northward shift

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N. Vigaud, A.W. Robertson, and M. K. Tippett

America than in Europe, despite previous studies demonstrating the advantages of weather typing over the United States ( Robertson and Ghil 1999 ; Stan and Straus 2007 ; Riddle et al. 2013 ; Robertson et al. 2015 ). The North American continent and upstream Pacific are both much larger and complex, and hence, there is a need to improve our knowledge of the influence of WRs on North American climate and underlying physical processes and to assess their S2S predictability. The reduced-order WR view

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Alicia M. Bentley, Lance F. Bosart, and Daniel Keyser

association with damaging winds and heavy precipitation (e.g., Salmon and Smith 1980 ; Gyakum 1983a , b ; Uccellini et al. 1984 , 1985 ; Hakim et al. 1995 , 1996 ; Mailier et al. 2006 ; Dacre et al. 2012 ). Particularly strong ECs forming over and traversing densely populated regions of central and eastern North America have the potential to lead to extreme weather events (EWEs), defined in the present study as high-impact weather events that are societally disruptive, geographically widespread

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Andrew C. Winters, Daniel Keyser, Lance F. Bosart, and Jonathan E. Martin

climatology of Northern Hemisphere jet superpositions using the NCEP–NCAR reanalysis dataset ( Kalnay et al. 1996 ; Kistler et al. 2001 ) during November–March 1960–2010 indicates that jet superpositions are most frequent over the western North Pacific, North America, and northern Africa ( Christenson et al. 2017 ). The key dynamical processes associated with western North Pacific jet superpositions have been examined in detail by Handlos and Martin (2016) . These dynamical processes include equatorward

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Andrew J. Newman and Richard H. Johnson

1. Introduction The North American monsoon (NAM) has the typical characteristics of a monsoon: a seasonal wind reversal and areas receiving a significant portion of their annual precipitation during the NAM ( Carleton et al. 1990 ; Badan-Dangon et al. 1991 ; Douglas et al. 1993 ; Douglas 1995 ; Stensrud et al. 1995 ; Adams and Comrie 1997 ; Anderson et al. 2000a ; Vera et al. 2006 ; Johnson et al. 2007 ). Regions in the core of the monsoon (northwest Mexico) receive up to 80% of their

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Neil P. Lareau and John D. Horel

Hemisphere storm tracks have been studied in depth for better than half a century ( Petterssen 1956 ; Klein 1957 ; Blackmon 1976 ; Sickmöller et al. 2000 ; Hoskins and Hodges 2002 , hereafter HH02 ; Wettstein and Wallace 2010 ). Storm tracks are also of manifest regional importance. The occurrence and progression of storms across western North America have a significant impact on the region’s hydrologic cycle during the cool season (October–April), particularly in terms of the development of

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Andrew J. Newman and Richard H. Johnson

1. Introduction Gulf surge events, or surge events for short, are critical transient events in the North American monsoon (NAM) because they have been tied to moisture flux and precipitation anomalies during the NAM ( Anderson et al. 2000a ; Berbery 2001 ; Douglas and Leal 2003 ; Gochis et al. 2004 ; Higgins et al. 2004 ) and severe weather outbreaks in Arizona ( Maddox et al. 1995 ). Most of the large-scale features associated with the initiation of a surge event were first identified over

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