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Tianjiao Ma, Wen Chen, Hans-F. Graf, Shuoyi Ding, Peiqiang Xu, Lei Song, and Xiaoqing Lan

local climate anomalies over East Asia, but also exerts remote impacts on its downstream regions of the Pacific and North America (NA) ( Chang and Lau 1980 ; Compo et al. 1999 ; Chen et al. 2000 ; Ha et al. 2012 ; Jia et al. 2015 ; Song et al. 2016 ; Yu et al. 2018 ). Many previous studies mainly focused on understanding the processes of external forcing and atmospheric internal variability affecting the EAWM variability, such as El Niño–Southern Oscillation (ENSO) ( Zhang et al. 1996 , 1999

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Patrick Kelly and Brian Mapes

1. Introduction The North American monsoon (NAM) is a circulation pattern that brings summer rains to northwest Mexico and the southwest United States (see Adams and Comrie 1997 for a review). Synoptically, summer rainfall of the NAM involves moisture circulated by a “dirty ridge,” that is, an anticyclone in the lower-middle free troposphere marked by deep convection. This anticyclone can be thought of as the top part of a thermal low that develops in the desert Southwest ( Tang and Reiter

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Jeremy J. Mazon, Christopher L. Castro, David K. Adams, Hsin-I Chang, Carlos M. Carrillo, and John J. Brost

sounding are discussed later in the next section. The time period considered for the analysis is from 1993 to 2010. To define large-scale atmospheric circulation characteristics, we use the North American Regional Reanalysis (NARR; Mesinger et al. 2006 ). b. Stage IV precipitation product To verify the development and propagation of severe convective events, the combined stage IV radar–gauge precipitation product, as described by Zhang et al. (2011) , is used for the period 2002–10. This dataset is a

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Liang Chen and Paul A. Dirmeyer

sensitivity of convection to land conditions is expected to be the greatest during this season and time of day ( Dirmeyer et al. 2003 ; Song et al. 2016 ; Taylor et al. 2012 ). Many studies have documented land-atmosphere interactions over North America, especially concentrating on how land surface conditions (such as soil moisture, surface heating, and evaporative fraction) influence the atmosphere (e.g., Alfieri et al. 2008 ; Dirmeyer et al. 2013 ; Findell et al. 2011 ; Tawfik et al. 2015 ). Also

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Shannon M. Jones and David S. Gutzler

1. Introduction Climate model projections indicate that arid conditions throughout southwestern North America (SWNA) will amplify over the next century as a function of long-term trends in precipitation ( P ) and evaporation ( E ) ( Seager et al. 2007 ; Hoerling and Eischeid 2007 ; Gutzler and Robbins 2011 ; Cook et al. 2015 ). Increasing evidence suggests this is already happening ( Garfin et al. 2014 ), although detecting long-term trends distinct from episodic droughts in real time is

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Richard Seager, David Neelin, Isla Simpson, Haibo Liu, Naomi Henderson, Tiffany Shaw, Yochanan Kushnir, Mingfang Ting, and Benjamin Cook

1. Introduction The North American hydroclimate is marked by stark contrasts with semiarid to arid regions in the U.S. Southwest; wet subtropical, temperate, and continental climates to the east and north; and the Great Plains characterized by a remarkably strong west to east dry to wet transition. All model-based analyses of the impacts of rising greenhouse gases on North American climate project that these contrasts will become even more marked in the coming century. This occurs as part of a

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Alexis Berg, Kirsten Findell, Benjamin R. Lintner, Pierre Gentine, and Christopher Kerr

before-noon surface heat flux partitioning on subsequent afternoon rainfall during the summer season in the United States and Mexico using data from the North American Regional Reanalysis (NARR; Mesinger et al. 2006 ). Given that NARR assimilates hourly rainfall and screen-level air temperature measurements and that surface turbulent fluxes are strongly constrained by the assimilation of near-surface data ( Mahfouf 1991 ; Bouttier et al. 1993 ), NARR arguably represents a reasonable approximation

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Justin Sheffield, Suzana J. Camargo, Rong Fu, Qi Hu, Xianan Jiang, Nathaniel Johnson, Kristopher B. Karnauskas, Seon Tae Kim, Jim Kinter, Sanjiv Kumar, Baird Langenbrunner, Eric Maloney, Annarita Mariotti, Joyce E. Meyerson, J. David Neelin, Sumant Nigam, Zaitao Pan, Alfredo Ruiz-Barradas, Richard Seager, Yolande L. Serra, De-Zheng Sun, Chunzai Wang, Shang-Ping Xie, Jin-Yi Yu, Tao Zhang, and Ming Zhao

1. Introduction This is the second part of a three-part paper on phase 5 of the Coupled Model Intercomparison Project (CMIP5; Taylor et al. 2012 ) model simulations for North America. This second part evaluates the CMIP5 models in their ability to replicate the observed variability of North American continental and regional climate, and related climate processes. Sheffield et al. (2013 , hereafter Part I) evaluate the representation of the climatology of continental and regional climate

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Weina Guan, Xianan Jiang, Xuejuan Ren, Gang Chen, Pu Lin, and Hai Lin

winter, surface air temperature (SAT) exhibits pronounced intraseasonal variability over the mid- to high latitudes of the Northern Hemisphere ( Lin and Brunet 2009 ; Lin 2015 ; Collow et al. 2019 ; Lin 2018 ; Stan and Krishnamurthy 2019 ; also see Fig. 1 ). These persistent SAT anomalies on the intraseasonal time scale can be closely related to regional extreme warm and cold episodes over North America (NA; e.g., Katz and Brown 1992 ), exerting significant influence on daily life, public

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Renaud Barbero, John T. Abatzoglou, and Katherine C. Hegewisch

the potential utility of such forecasts for water resources and wildfire management (e.g., Hartmann et al. 2002 ). Recent studies have demonstrated the utility of statistical downscaling over raw GCM output for reproducing monthly climatic statistics and extremes for both climate scenarios ( Ning et al. 2012 ; Ahmed et al. 2013 ; Ning et al. 2015 ) and seasonal climate forecasting ( Yoon et al. 2012 ). To address this gap, we assess in this study the skill of North American Multimodel Ensemble

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