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Shiqiu Peng, Yineng Li, and Lian Xie

assimilation. The improvements of the storm surge forecasts can be attributed to the correction of wind stress bias caused by the erroneous wind speed (CTRL_V− or CTRL_V+) through the optimal obtained by 4DVAR, as shown in Fig. 10 . For most operational storm surge forecasting systems, systematic bias may exist in the calculation of the surface wind fields using the Holland model or other empirical models. The results of this set of ITEs indicate that the systematic bias in the surface wind fields can

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Zhiqiang Cui, Zhaoxia Pu, G. David Emmitt, and Steven Greco

goal of this paper is to examine the impact of the high-temporal-resolution wind data from DAWN on short-range numerical simulations of tropical convective systems. Specifically, we choose two convective cases occurring during CPEX over the Gulf of Mexico and the Caribbean Sea to evaluate the analysis and forecast impact of DAWN wind profiles. In addition, different assimilation methods are used and compared to assimilate the wind profiles. The paper is organized as follows. In section 2 , the

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Zhijin Li, Yi Chao, James C. McWilliams, and Kayo Ide

region increase, real-time monitoring and forecasting become increasingly important. In response to its scientific and economic importance, there are ongoing efforts in the federal and state government to establish a network of coastal ocean observing systems that will suit both research and operational needs ( National Research Council 2003 ). As a consequence, we have been seeing an explosive development of new observational tools and platforms. Development in satellite oceanography provides

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Daniel Birkenheuer and Seth Gutman

1. Introduction The International H 2 O Project (IHOP-2002), a multiagency field experiment over the southern Great Plains of North America from 13 May to 25 June 2002, was undertaken to improve the characterization of water vapor variability in time and space and the understanding and prediction of convection. The primary focus of the Forecast Systems Laboratory (FSL) was to examine the ability to measure and analyze water vapor in several preconvective environments, including convective

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N. Andrew Crook and Juanzhen Sun

. The system has been under development for approximately 5 yr and has been run operationally for the past 2 yr at the Weather Forecast Office in Sterling, Virginia, using data from a single WSR-88D radar. The single-Doppler assimilation system is described in detail in Sun and Crook (2001) . Recently, we enhanced the system to assimilate data from multiple Doppler radars. This system was run at the Bureau of Meteorology in Sydney, Australia, as part of a Forecast Demonstration Project (FDP). The

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Theodore Mettlach, David Wang, and Paul Wittmann

Wittmann and Clancy( 1991 ). The GSOWM is a first-generation wave modelthat is run operationally at FNOC. The model is forcedby the winds produced by the Navy Operational GlobalAtmospheric Forecasting System Prediction model andis run on a 2.5- spherical grid twice per day. GSOWMproduces two-dimensional wave spectra up to a forecasttime of 72 h with a resolution of 15 frequencies by 24directions. The initial conditions for these forecasts areprovided by carrying the predicted, two

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Sebastián M. Torres and Christopher D. Curtis

1. Introduction When considering tornado warnings, National Weather Service (NWS) forecasters routinely assess the strength of Doppler radar tornadic vortex signatures (TVSs) or tornado signatures (TSs) by evaluating their rotational velocity through the azimuthal gate-to-gate Doppler velocity difference (e.g., Brown et al. 1978 ; Mitchell et al. 1998 ). Unfortunately, the detection of smaller, weaker, and/or more distant tornadoes using radar is more challenging because of the curvature of

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Qin Xu, Kang Nai, and Valery Melnikov

satisfy the primary need for visual applications at the weather forecast offices), the processed velocity data are not free of serious aliasing errors especially for velocities scanned with VCP31 [see Tables 1–3 of Witt et al. (2009) ], and thus cannot satisfy the high-quality standard required by operational data assimilation at NCEP. To meet the need of radar data assimilation, persistent efforts have been made at NSSL to develop robust dealiasing techniques ( Gong et al. 2003 ; Gao et al. 2004

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Olivier Caumont, Véronique Ducrocq, Guy Delrieu, Marielle Gosset, Jean-Pierre Pinty, Jacques Parent du Châtelet, Hervé Andrieu, Yvon Lemaître, and Georges Scialom

(AROME), is planned to be operational by 2008. It is being designed to run at a resolution of only a few kilometers. The National Center for Atmospheric Research (NCAR), the National Oceanic and Atmospheric Administration (NOAA), the Center for Analysis and Prediction of Storms (CAPS), and a number of scientists at universities are also working together on the Weather Research and Forecasting (WRF) model, which is intended to supersede existing models from all these institutions (see information

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James Foster, Ning Li, and Kwok Fai Cheung

Oceanic and Atmospheric Administration (NOAA)/NCEP operational global-scale WAVEWATCH III model. The global model is initialized daily and is forced with NOAA/NCEP’s Global Forecast System (GFS) winds. This model is designed to capture the large-scale ocean waves in a 180-h (7.5 days) forecast. 3. Results a. Significant wave height Although there are many parameters to describe the statistical properties of the sea surface, we focus here on the most widely used: the significant wave height (SWH), and

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