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Juerg Schmidli, Brian Billings, Fotini K. Chow, Stephan F. J. de Wekker, James Doyle, Vanda Grubišić, Teddy Holt, Qiangfang Jiang, Katherine A. Lundquist, Peter Sheridan, Simon Vosper, C. David Whiteman, Andrzej A. Wyszogrodzki, and Günther Zängl

, J. D. Fast , M. W. Rotach , and S. Zhong , 2005 : The performance of RAMS in representing the convective boundary layer structure in a very steep valley . Environ. Fluid Mech. , 5 , 35 – 62 . Deardorff , J. W. , 1980 : Stratocumulus-capped mixed layers derived from a 3-dimensional model . Bound.-Layer Meteor. , 18 , 495 – 527 . Doms , G. , and Coauthors , 2007 : A description of the nonhydrostatic regional model LM: Part II: Physical parameterization . Tech. Rep., DWD

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Juerg Schmidli, Gregory S. Poulos, Megan H. Daniels, and Fotini K. Chow

with the Sierra Nevada mountains and not due to local thermal forcing. 6. Conclusions Numerical experiments are performed using ARPS aimed at understanding the differences in observed flow evolution in California’s Owens Valley for two nights that were expected to be dominated by local thermally driven valley winds due to the presence of a weak high pressure ridge. The performance of ARPS has been evaluated through comparison with data from the T-REX field campaign. The model is able to reproduce

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Stephan F. J. De Wekker and Shane D. Mayor

instruments. We also intend to use the lidar data to evaluate the performance of mesoscale models and particle dispersion models over mountainous terrain. We have shown that a rapidly scanning ground-based aerosol lidar can significantly contribute to an improved understanding of mountain meteorological phenomena, and we encourage the research community to use the dataset in support of their observational analysis and/or modeling efforts. Acknowledgments The National Center for Atmospheric Research is

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Bowen Zhou and Fotini Katopodes Chow

240-m LES grid, however, to a reduced magnitude. Model performance is less satisfactory after 2110 LST. On the LES grid, temperature is underpredicted by ~2°C, wind speed by ~5 m s −1 , and direction by 20° with a maximum deviation of 45° from the observation at 2124 LST. Despite the deviations, surface streamlines still indicate a down-valley-flow-dominated region around the central tower (not shown). The general conclusion of down-slope to down-valley flow transition still holds in the model

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Patrick A. Reinecke and Dale R. Durran

Kalman filter. Mon. Wea. Rev. , 130 , 2791 – 2808 . Nance , L. B. , and B. R. Coleman , 2000 : Evaluating the use of a nonlinear two-dimensional model in downslope windstorm forecasts. Wea. Forecasting , 15 , 717 – 729 . Nastrom , G. D. , and D. C. Fritts , 1992 : Sources of mesoscale variability of gravity waves. Part I: Topographic excitation. J. Atmos. Sci. , 49 , 101 – 110 . Peltier , W. R. , and T. L. Clark , 1979 : The evolution and stability of finite

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Michael Hill, Ron Calhoun, H. J. S. Fernando, Andreas Wieser, Andreas Dörnbrack, Martin Weissmann, Georg Mayr, and Robert Newsom

the behavior given in the analysis of Lhermitte and Miller (1970) for a dual-radar, coscanned plane, as shown in ( Fig. 12 ). e. Noise pollution Our model was tested numerically with varying levels of independent random noise to synthetically pollute the data, rather than the direct evaluation of uncertainty statistics in each bin. The evaluation of 3D matrices that were a consequence of these statistics caused computer memory issues and became time prohibitive. The radial velocity data were

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Ronald B. Smith, Bryan K. Woods, Jorgen Jensen, William A. Cooper, James D. Doyle, Qingfang Jiang, and Vanda Grubišić

trapped waves can be added separately. The wave amplitude and vertical wavelength adjust smoothly to each atmospheric layer encountered as the wave propagates upward. While this model neglects wave reflection, it captures the wave amplification due to decreasing wind and density aloft. In the discrete layered approach to linear wave theory, property variations are assumed to be abrupt. Vertical displacement and pressure are matched across each interface and these interface conditions are used to find

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Junhong Wang, Jianchun Bian, William O. Brown, Harold Cole, Vanda Grubišić, and Kate Young

://www.vaisala.com/weather/products/soundingequipment/dropsonde .] . Van Zandt, T. E. , 2000 : A brief history of the development of wind-profiling or MST radars. Ann. Geophys. , 18 , 740 – 749 . 10.1007/s00585-000-0740-4 Vennard, J. K. , 1955 : Elementary Fluid Mechanics . 7th ed. John Wiley & Sons, 401 pp . Wang, J. , 2005 : Evaluation of performance of the dropsonde humidity sensor using data from DYCOMS-II and IHOP_2002. J. Atmos. Oceanic Technol. , 22 , 247 – 257 . 10.1175/JTECH1698.1 Fig . 1. The rise rate (m s −1 ) in the actual and still

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Susanne Drechsel, Georg J. Mayr, Michel Chong, Martin Weissmann, Andreas Dörnbrack, and Ronald Calhoun

vertical velocity observed with a scannable C-band radar and two UHF profilers in the lower troposphere. J. Atmos. Oceanic Technol. , 19 , 899 – 910 . 10.1175/1520-0426(2002)019<0899:CORRAV>2.0.CO;2 Martner, B. , and Coauthors , 1993 : An evaluation of wind profiler, RASS, and microwave radiometer performance. Bull. Amer. Meteor. Soc. , 74 , 599 – 613 . 10.1175/1520-0477(1993)074<0599:AEOWPR>2.0.CO;2 Newsom, R. K. , Ligon D. , Calhoun R. , Heap R. , Cregan E. , and Princevac M

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Stephen A. Cohn, Vanda Grubiššićć, and William O. J. Brown

waves and rotors as well as simulations of valley flows under more quiescent conditions. This includes the performance of forecast and research models under such conditions and simulation of small-scale features of rotors ( Doyle et al. 2009 , 2011 ; Schmidli et al. 2011 ). In turn, interpretation of the observations benefits from insights gained from the model simulations. Prior to T-REX and SRP, the majority of observations of rotors and the conditions surrounding them were made in the four

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