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Rolf H. Langland, Christopher Velden, Patricia M. Pauley, and Howard Berger

roughly half as large as those assigned to AMV wind super-obs at similar pressure levels. 3. Experimental design To test the model forecast impact of the RS winds, we designed four experiments, summarized in Table 1 . In all experiments, satellite wind observations are assimilated as super-obs. The control forecast (CNO) uses only the regular (e.g., “operational”) satellite wind data (AMVs), and no AMVs are used over the land area of North America. In a variation of the control, called experiment CNL

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Fuqing Zhang, Yonghui Weng, Jason A. Sippel, Zhiyong Meng, and Craig H. Bishop

final analysis time after the storm begins its rapid weakening over land, the EnKF analysis correctly places the center of the storm over the Texas–Louisiana border. It also correctly analyzes the broad rainbands to the east of the storm ( Figs. 7g and 7h ). The NoDA ensemble forecast mean, on the other hand, does not simulate any tropical development ( Figs. 7c, 7f, and 7i ). b. Deterministic forecasts from the EnKF analysis Next, we examine the value that using EnKF to assimilate Vr adds to

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Hyun Mee Kim and Byoung-Joo Jung

correlations for the second and third SVs shown in Table 3 , which implies that the linearity is degraded for the second and third SVs. 6. Summary and discussion In this study, the horizontal structures, vertical distributions, and growth rates of SVs for Typhoon Usagi were investigated using different moist physics and norms. The MM5, its tangent linear, and adjoint models with a Lanczos algorithm were used to calculate SVs, which maximize the tropospheric TE over a region including land and ocean near

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Sim D. Aberson

conducted when a tropical cyclone approaches land, usually starting when a threat during the forecast period is identified and logistics allow the mission, and ending either about 24 h before final landfall, when all preparations should be completed, or when the threat no longer exists. In Aberson (2002 , 2003) , each surveillance mission was assessed individually: dropwindsonde data obtained in previous missions were not used in the parallel run for the mission being assessed. Since 1999, assessments

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Ryan D. Torn and Gregory J. Hakim

scheme ( Kain and Fritsch 1990 ), Yonsei University (YSU) boundary layer scheme ( Hong et al. 2006 ), and the Noah land surface model ( Ek et al. 2003 ). An ensemble of lateral boundary conditions for the outer domain is obtained using the fixed-covariance perturbation (FCP) technique of Torn et al. (2006) . Ensemble lateral boundary conditions are derived by drawing random perturbations from the WRF VAR system ( Barker et al. 2004 ), which are scaled by 1.7, and subject to a temporal

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Peter Black, Lee Harrison, Mark Beaubien, Robert Bluth, Roy Woods, Andrew Penny, Robert W. Smith, and James D. Doyle

1. Introduction Widely used tropical cyclone (TC) models include regional air–sea coupled dynamical models such as COAMPS-TC ( Jin et al. 2014 ), HWRF ( Tallapragada et al. 2014 ; Kim et al. 2014 ) and GFDL ( Bender et al. 2007 ; Gall et al. 2011 ); global dynamical models such as GFS and ECMWF; and statistical–dynamical intensity-prediction models such as SHIPS, the Statistical Typhoon Intensity Prediction Scheme (STIPS), the Logistic Growth Equation Model (LGEM), and the rapid intensity

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