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Brian C. Ancell, Erin Kashawlic, and John L. Schroeder

assimilated were sparse, a result first discussed in Hamill and Snyder (2000) . At finer grid spacing (30 km), Meng and Zhang (2008a) and Meng and Zhang (2008b) showed improved forecast performance with an EnKF over that of 3DVAR with the Weather Research and Forecasting (WRF) Model for a mesoscale convective vortex and a month-long experiment verifying against radiosonde data. Meng and Zhang (2008b) assimilated only radiosonde data (relatively sparse), whereas Meng and Zhang (2008a) assimilated

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A. Amengual, D. S. Carrió, G. Ravazzani, and V. Homar

and Kalnay 1993 ; Mullen and Baumhefner 1988 ; Houtekamer and Derome 1995 ; Du et al. 1997 ). Indeed, errors of any origin can grow rapidly during the quantitative precipitation forecasting and steer toward misleading predictions, especially when fast-growing modes, such as those leading mesoscale convective developments, are dominant for the predicted field. Therefore, QPF is highly sensitive to errors in the initial conditions (ICs), lateral boundary conditions (LBCs), and model physical

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Haidao Lin, Stephen S. Weygandt, Agnes H. N. Lim, Ming Hu, John M. Brown, and Stanley G. Benjamin

framework mimicking that of the operational North American Mesoscale Forecast System (NAM), McCarty et al. (2009) showed at 48 h a forecast improvement in geopotential height at 500 hPa, defined as the time difference in hours at which the forecasts fall below two points of equal anomaly correction, is 2.3 h. They also showed improvement of 8% and 7% in equitable threat and bias scores of precipitation forecasts of 25 mm (6 h) −1 . Using a similar framework, Lim et al. (2014) showed improvement in

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David R. Novak, Jeff S. Waldstreicher, Daniel Keyser, and Lance F. Bosart

frontogenesis northwest of the surface cyclone ( Fig. 1b ). These results are also consistent with the case study work of Martin (1998a , b ), Banacos (2003) , and Moore et al. (2005) , who have documented similar synoptic and mesoscale flow evolutions in case studies of mesoscale banding in the central and eastern United States. These emerging conceptual models of the synoptic and mesoscale flow environments conducive to band formation are providing forecasters with an awareness of the potential for

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Morris A. Bender, Timothy P. Marchok, Charles R. Sampson, John A. Knaff, and Matthew J. Morin

of this paper. In the few studies that exist in the literature, the quality of the wind radii estimates provided in the TC vitals has been found to have an impact on TC-focused NWP forecasts. For example, Kunii (2015) found that the inclusion of wind radii data helped improve TC track forecasts in the Japan Meteorological Agency’s (JMA) operational mesoscale model. Also, Marchok et al. (2012) showed that modifying the observed 34- and 50-kt wind radii used to initialize the GFDL hurricane

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Nina Schuhen, Thordis L. Thorarinsdottir, and Tilmann Gneiting

; Thorarinsdottir and Gneiting 2010 ; Thorarinsdottir and Johnson 2012 ). However, in many of the aforementioned applications it is important to honor the full information about the bivariate structure of the future wind vector that is provided by the ensemble. Thus, our EMOS postprocessed forecasts take the form of elliptically symmetric bivariate normal densities, as illustrated in Fig. 1 in an application to the University of Washington Mesoscale Ensemble (UWME; Eckel and Mass 2005 ). A description of

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Mei Xu, David J. Stensrud, Jian-Wen Bao, and Thomas T. Warner

development. As the temporal and spatial scales of interest become smaller, many more instabilities and processes are known to play a significant role, at least intermittently, in the evolution of the atmosphere at a given location. The skill of numerical models in predicting the variety of mesoscale and small-scale phenomena is not well known, since our ability to observe these phenomena is limited. However, if one examines summertime quantitative precipitation forecasts associated with mesoscale

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Dennis G. Baker

VOL. I10, NO. 3 MONTHLY WEATHER REVIEW MARCH 1982Synoptic-Scale and Mesoscale Contributions to Objective Operational Maximum Minimum Temperature Forecast Errors DENNIS G. BAKERDepartment of Atmospheric and Oceanic Science, University of Michigan. Ann Arbor 48109(Manuscript received 13 July 1981, in final form 30 December 1981 ) ABSTRACT Root-mean-square errors of the

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Ryan A. Sobash and David J. Stensrud

that can be resolved at convection-allowing model resolutions. For example, the number of mesoscale surface observation networks (i.e., mesonets) have increased during the past several years, and methods to gather, quality control, and distribute these observations in real time have matured. These networks often provide data at higher spatial and temporal resolution than conventional observing systems (e.g., Automated Surface Observing Systems), and are routinely used by forecasters in real time to

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Daniel T. Dawson II and Ming Xue

the assimilation cycles or assimilation window, a final analysis is produced that provides the initial condition for a subsequent model forecast. When the initial condition is based on an analysis at a single time, and especially when the analysis background is from the forecast of a different model, the subsequent forecast is often referred to as “cold starting” from such initial conditions. No matter how the initial conditions are derived, for mesoscale and storm-scale NWP, they should contain

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