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Thomas M. Hamill

impossible to reach, except on foot. A total of 30 state highway bridges were destroyed and 20 were severely damaged. In addition, 27 state dams sustained damage; 150 miles of railroad track were damaged. Nine people died as a result of the storms and flooding. This article will analyze the performance of operational precipitation forecasts over the northern Front Range, especially Boulder County, though the maps herein will allow the reader to examine the performance of the models over larger regions

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James S. Goerss

Prediction (NCEP), the Navy Operational Global Atmospheric Prediction System (NOGAPS; Hogan and Rosmond 1991 ; Goerss and Jeffries 1994 ) run at the Fleet Numerical Meteorology and Oceanography Center (FNMOC), and the Met Office global model (UKMO; Cullen 1993 ; Heming et al. 1995 ). The improvement in the TC track forecasting skill of the global NWP models since 1992 has been illustrated for both the western North Pacific Ocean ( Goerss et al. 2004 ) and the Southern Hemisphere ( Sampson et al. 2005

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Kevin Bachmann, Christian Keil, George C. Craig, Martin Weissmann, and Christian A. Welzbacher

1. Introduction Convection-permitting numerical weather prediction (NWP) models underpin a step change for operational forecasting centers in their struggle to predict thunderstorms and convective precipitation ( Clark et al. 2016 ) as they allow some key issues to be addressed. First, the intrinsically limited predictability of the small scales, including convection, necessitates the use of ensembles to generate probabilistic forecasts and assess their confidence ( Lorenz 1969 ; Slingo and

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Thomas M. Hamill, Jeffrey S. Whitaker, Daryl T. Kleist, Michael Fiorino, and Stanley G. Benjamin

1. Introduction Recently, Hamill et al. (2011 , hereafter H11 ) verified global ensemble predictions of 2009’s Northern Hemisphere summer tropical cyclone forecasts initialized with a global ensemble Kalman filter (EnKF) system. The assimilation and forecasts were performed at a relatively high resolution, T384L64, or approximately 31 km at 25°N. 1 The significant improvement of these experimental forecasts relative to the operational global ensemble guidance provided by the National Centers

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Xiaosong Yang, Timothy DelSole, and Hua-Lu Pan

of a model. Given the significant benefits that might follow from improving the skill of an operational weather forecast model, it is important to investigate whether an empirical correction method can indeed improve forecast skill. The study of DelSole et al. (2008) was based on the Center for Ocean–Land–Atmosphere Studies, version 3.2, (COLAv3.2) model, which is not an operational weather forecast model. In addition, the analyses used to verify the forecasts were generated by a data

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Aaron J. Hill, Gregory R. Herman, and Russ S. Schumacher

challenge in accurately forecasting the phenomena. Due to the very small spatial scales associated with severe weather, it is often exceedingly difficult to model dynamically with operational weather models. Production of large hail involves a plethora of very small-scale microphysical processes that are necessarily parameterized in numerical models. The microphysical simplifications involved to hasten production of operational model output, including bulk rather than bin schemes (e.g., Khain et al

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Luciana Bertotti, Luigi Cavaleri, Layla Loffredo, and Lucio Torrisi

1. Purpose of the work Nettuno is a high-resolution local-scale wind and wave forecast system operational in the Mediterranean Sea. Several parallel systems are available in this area, although often not on the whole basin. Some of these results are public domain (within limits), but a thorough analysis of the related performance is not a frequent product. A notable exception is the Joint Technical Commission for Oceanography and Marine Meteorology (JCOMM) intercomparison exercise focused on

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S. G. Gopalakrishnan, David P. Bacon, Nash'at N. Ahmad, Zafer Boybeyi, Thomas J. Dunn, Mary S. Hall, Yi Jin, Pius C. S. Lee, Douglas E. Mays, Rangarao V. Madala, Ananthakrishna Sarma, Mark D. Turner, and Timothy R. Wait

(1977) ; Anthes (1972 , 1977 , 1982) ; Kurihara (1973) ; Emanuel (1988) ; Bender et al. (1993) ; Kurihara et al. (1993 , 1995) ; Krishnamurti et al. (1995) ; Liu et al. (1997 , 1999) have all led to a better understanding of the structure and evolution of hurricanes (see, for instance, Liu et al. 1997 for a brief review on hurricane research). Yet, to date there is no operational model that can forecast both hurricane track and intensity reasonably well ( Emanuel 1999 ; Willoughby

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Jean-Jacques Morcrette, George Mozdzynski, and Martin Leutbecher

checked with only very small differences between R 159/ R 95 and R 95/ R 63. The EPS, operational since 5 June 2007, is therefore run at T L 399 L 62 R 95 then at T L 255 L 62 R 63. 5. Impact on high-resolution T L 799L91 10-day forecasts Results in terms of objective scores (i.e., anomaly correlation at different geopotential heights, rmse and mean errors in temperature and winds) when the radiation resolution is reduced, are not shown for the T L 799 L 91 forecasts as they are as or more

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Dennis S. Walts and Larry O. Pochop

VOL. 105, NO. 1 MONTHLY WEATHER REVIEW JANUARY 1977Operational Objective Temperature Forecasts at Non-MOS~ Stations DENNIS S. WALTS National Weather Service Forecast Offce, Cheyenne, Wyo. 82001 Laxly O. I)OCHOPAgricultural Engineering Division, University of Wyomlng2, Laramie 82071 (Manuscript received 6 July 1976, in revised form 15 October 1976)ABSTRACT A method is presented

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