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Eric A. Aligo, William A. Gallus Jr., and Moti Segal

relevant features affecting convection and their sensitivity to VGR are outlined: The higher the VGR of the ICs and LBCs, the more likely that refined observed features, such as the convective boundary layer (CBL) capping inversion, sharp wind shear, and low-level jets can be captured more accurately, thus improving the introduction of thermodynamic and some dynamical forcing. In mesoscale models, the cloud microphysical processes are resolved typically with a coarser VGR with increasing height

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Jingyu Wang, Xiquan Dong, Aaron Kennedy, Brooke Hagenhoff, and Baike Xi

the Southern Great Plains (SGP) of the United States, this was offset by a nocturnal, negative bias, whereas biases were predominantly positive over the Northern Great Plains (NGP). The segregation of model performance by meteorological regimes has been commonly used in the climate modeling community where ample data allow for separation of model performance by prevailing conditions or synoptic patterns. In turn, this can provide insight into model behavior (e.g., forcing mechanisms responsible

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David J. Nicosia, Ernest J. Ostuno, Nathaniel Winstead, Gabriel Klavun, Charles Patterson, Craig Gilbert, George Bryan, John H. E. Clark, and J. M. Fritsch

1. Introduction The occurrence of significant weather events as a direct result of forcing from the Great Lakes is well documented (e.g., Petterson and Calabrese 1959 ; Jiusto 1971 ; Hill 1971 ; Lavoie 1972 ; Lenschow 1973 ; Hjelmfelt 1990 ; Byrd et al. 1991 ; Ballentine et al. 1993 ; Sousounis and Fritsch 1994 ). Most of the notoriety of lake-effect events stems from the intense snow storms that occur downwind of individual lakes (e.g., over 1.5 m of snow fell near Cleveland, OH, on

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Paul J. Roebber, John R. Gyakum, and Diep N. Trat

in order to assess theability of an operational mesoscale model, the Canadian Regional Finite Element Model, to provide credibleforecast guidance concerning the regional distribution of precipitation associated with such events. The observeddistribution of the heaviest precipitation was dependent on the orientation and inland penetration of the coastalfront and its associated (geostrophic) frontogenetic forcing, although considerable local variability was evident.The observations indicate that

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Fernando Pereira de Oliveira and Marcos Daisuke Oyama

association between SLs and ITCZ ( Fig. 3 ). In July, the ITCZ is located far north of the CLA region (at ~7°N; Melo et al. 2009 ) and does not directly affect the SL initiation over the NCB. Therefore, the present work focuses on the SL initiation that is not related to the strong synoptic forcing (low-level atmospheric convergence) induced by the ITCZ. Fig . 3. Average frequency of SLs (cases per month) over the CLA region from 2005 to 2006. The number of cases related (unrelated) to the ITCZ is in

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A. Birol Kara, James B. Elsner, and Paul H. Ruscher

. Sensible heat flux is parameterized as H = ρ o C p C h ( θ s − θ o ). Other parameters are shown in the appendix. Details of the surface energy balance equation [ Eq. (23) ] and surface layer parameterizations can be found in Troen and Mahrt (1986) . c. Computational procedures The first step is to calculate the external forcing of the incoming solar radiation reduced by a fractional cloud cover. Fractional cloud cover computed from profiles of temperature and moisture from the previous time

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Ben A. Moser, William A. Gallus Jr., and Ricardo Mantilla

0.3, respectively. (See schematic in Fig. 3 .) To provide a scale-independent reference value for each link in the river network, the hydrological model was run for an 11-yr period from 2002 to 2012 using stage IV rainfall as forcing. This simulation allowed us to calculate a model-based mean annual flood (MAF) value for each link in the river network. The MAF calculated for each link allows us to define a flood severity index (FSI), which is calculated as the ratio between streamflow and MAF

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Paula Maldonado, Juan Ruiz, and Celeste Saulo

short-range ensemble forecasts to the horizontal localization cutoff radius and the magnitude of adaptive multiplicative inflation that is introduced based on a relaxation-to-prior spread approach (RTPS; Whitaker and Hamill 2012 ). In this work, we complement previous OSSE studies by taking model errors into account and using a realistic large-scale forcing. The rest of the paper is outlined as follows: Section 2 describes the design of our OSSEs, including the reference simulation and model

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Jessica R. Smith, Henry E. Fuelberg, and Andrew I. Watson

-scale forcing typically is weak, with little influence from midlatitude systems. Instead, mesoscale phenomena such as sea and lake breezes interact with their environments, surface features, and each other to produce complex patterns of convergence and convection. Our study domain spanned 28°–32°N and 87°–96°W, encompassing the northern Gulf of Mexico coastline and adjacent waters ( Fig. 1 ). As shown by Cummins et al. (1998) , five NLDN sensors are located within the area. Individual flashes were counted

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María CleoféValverde Ramírez, Nelson Jesus Ferreira, and Haroldo Fragade Campos Velho

rainfall process some kind of local persistence that presumably cannot be taken into account by the synoptic forcing process alone ( Zorita and von Storch 1999 ). Third, a measure of performance, the threat score (TS), is used that is more suitable than the correlation and rmse skills. This parameter is the most common measure of accuracy for ranking predictions of interest (i.e., rainfall above a certain threshold). Rainfall forecasts, especially for heavy and moderate events, are better ranked using

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