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Yun Lin, Jiwen Fan, Jong-Hoon Jeong, Yuwei Zhang, Cameron R. Homeyer, and Jingyu Wang

, 2007 : Simulations of cumulus clouds using a spectral microphysics cloud-resolving model . J. Geophys. Res. , 112 , D04201 , https://doi.org/10.1029/2006JD007688 . Fan , J. , R. Zhang , W.-K. Tao , and K. I. Mohr , 2008 : Effects of aerosol optical properties on deep convective clouds and radiative forcing . J. Geophys. Res. , 113 , D08209 , https://doi.org/10.1029/2007JD009257 . Fan , J. , L. R. Leung , Z. Li , H. Morrison , H. Chen , Y. Zhou , Y. Qian , and

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Stacey M. Hitchcock and Russ S. Schumacher

several different methods of classification, but two distinct categories consistently emerge for events over the central Great Plains. In synoptic-type events, a strong midtropospheric trough and slow moving surface front lead to strong forcing for ascent in a region with southerly flow and associated moisture transport. During the warm season, isentropic ascent of warm, moist air transported by the nocturnal low-level jet (LLJ) can lift an air to saturation on the cool side of a stationary or warm

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J. W. Wilson, S. B. Trier, D. W. Reif, R. D. Roberts, and T. M. Weckwerth

storms in the current case. However, when this effect is combined with the large 800–600-hPa vertical shear in the layer near and above cloud base ( Fig. 7 ), which itself is detrimental to the early stages of CI, and the fact that the mesoscale forcing in this case ( Fig. 10b ) was not strong, it is not surprising that relatively few deep convective storms occurred. b. Winds and thermodynamic stability Insight into the winds and stability in the vicinity of CI-H is provided in Fig. 14 . Shown are

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Thomas R. Parish and Richard D. Clark

forcing of the Great Plains low-level jet . J. Atmos. Sci. , 67 , 2690 – 2699 , doi: 10.1175/2010JAS3368.1 . 10.1175/2010JAS3368.1 Parish , T. R. , and D. Leon , 2013 : Measurement of cloud perturbation pressures using an instrumented aircraft . J. Atmos. Oceanic Technol. , 30 , 215 – 229 , doi: 10.1175/JTECH-D-12-00011.1 . 10.1175/JTECH-D-12-00011.1 Parish , T. R. , A. R. Rodi , and R. D. Clark , 1988 : A case study of the summertime Great Plains low level jet . Mon. Wea. Rev

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Thomas R. Parish

). It is appropriate to acknowledge the wide variety of local wind maxima described in the literature that have been identified by the term low-level jet (e.g., Stensrud 1996 ). In the discussion that follows, the focus is on the summertime Great Plains nocturnal maximum. Jet profiles linked to transient synoptic disturbances and those tied to the lower branch of a transverse circulation associated with an upper-level jet stream ( Uccellini 1980 ) are not considered. Forcing mechanisms for the

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Thomas R. Parish

central United States during the 1993 flood-altered terrain simulations . Mon. Wea. Rev. , 132 , 396 – 403 , doi: 10.1175/1520-0493(2004)132<0396:ROTIFL>2.0.CO;2 . Parish , T. R. , and L. D. Oolman , 2010 : On the role of sloping terrain in the forcing of the Great Plains low-level jet . J. Atmos. Sci. , 67 , 2690 – 2699 , doi: 10.1175/2010JAS3368.1 . Parish , T. R. , and D. Leon , 2013 : Measurement of cloud perturbation pressures using an instrumented aircraft . J. Atmos. Oceanic

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Sean Stelten and William A. Gallus Jr.

challenging. Although previous studies had shown that quantitative precipitation forecast skill increased as the strength of the large-scale forcing increased ( Jankov and Gallus 2004 ; Szoke et al. 2004 ), Duda and Gallus (2013) found that CI forecast skill in 3-km horizontal grid spacing versions of the Weather Research and Forecasting (WRF) Model did not follow such trends. Wilson and Roberts (2006) , however, found that CI tended to be better predicted in a 10-km version of the Rapid Update Cycle

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Manda B. Chasteen, Steven E. Koch, and David B. Parsons

simultaneously (e.g., Schumacher 2015 ). Additionally, strong dynamical forcing associated with mature convection may be sufficient to lift conditionally unstable air within the near-surface stable layer to its level of free convection (LFC), enabling nocturnal convection to remain surface based (e.g., Parker 2008 ; Nowotarski et al. 2011 ; Billings and Parker 2012 ). The degree to which nocturnal convection is surface based is often uncertain and thus creates complications for forecasters, who may

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Tammy M. Weckwerth, Kristy J. Weber, David D. Turner, and Scott M. Spuler

vapor profiles but clouds, which often occur in dynamic weather conditions, obscure the BL because clouds are usually optically thick in the infrared. Since ground-based MWRPs require periodic manual calibration, systematic biases in the calibration (e.g., Paine et al. 2014 ) can occur that impact the retrieved thermodynamic profiles (e.g., Löhnert and Maier 2012 ), and they have only limited information content, resulting in poor vertical resolution ( Löhnert et al. 2009 ). Ground-based infrared

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Coltin Grasmick, Bart Geerts, David D. Turner, Zhien Wang, and T. M. Weckwerth

night of 15 July 2015 in western Kansas as part of the Plains Elevated Convection at Night (PECAN) field campaign ( Geerts et al. 2017 ). This MCS propagated forward (to the east) relatively rapidly, faster than the deep-layer mean westerly flow. Such MCS motion commonly occurs from discrete propagation ( Bodine and Rasmussen 2017 ), during which the MCS merges with new convective cells triggered by cold pool or gravity wave forcing ( Crook and Moncrieff 1988 ; Corfidi 2003 ; Fovell et al. 2006

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