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Robert F. Rogers, Michael L. Black, Shuyi S. Chen, and Robert A. Black

distribution of latent heat release is quite challenging, however, and improving our understanding and forecasting of intensity and rainfall remains an elusive goal for the operational and research communities. For example, the forecast skill for intensity is only about one-half (one-third) of that for track at 36 h (72 h) forecast time ( DeMaria and Gross 2003 ), while standardized techniques for evaluating tropical cyclone rainfall are only now being developed ( Marchok et al. 2007 ). Continuing

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Jason A. Sippel, Scott A. Braun, and Chung-Lin Shie

, M. , J. A. Knaff , and B. H. Connell , 2001 : A tropical cyclone genesis parameter for the tropical Atlantic . Wea. Forecasting , 16 , 219 – 233 . Doswell , C. A. , III , and E. N. Rasmussen , 1994 : The effect of neglecting the virtual temperature correction on CAPE calculations . Wea. Forecasting , 9 , 625 – 629 . Dudhia , J. , 1989 : Numerical study of convection observed during the winter monsoon experiment using a mesoscale two-dimensional model . J. Atmos. Sci

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Brian A. Colle, Matthew F. Garvert, Justin B. Wolfe, Clifford F. Mass, and Christopher P. Woods

description The PSU–NCAR mesoscale model was used in a nonhydrostatic mode to simulate this case. Garvert et al. (2005a) describes the detailed setup of the MM5 simulations for the 13–14 December event, which included a 36-km grid covering the eastern Pacific and western North American and nested down to a 1.33-km grid over the central Oregon Cascades ( Fig. 1 ). The 6-h National Centers for Environmental Prediction (NCEP) analysis and subsequent forecasts from the Global Forecast System (GFS) model at

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Thomas Kilpatrick, Niklas Schneider, and Bo Qiu

. Section 3 describes the free-atmosphere response to the SST front, and section 4 describes the MABL response. Section 5 provides a summary and discussion, including a recommendation for an MABL model that is well suited for SST frontal zones. 2. Regional atmospheric model configuration The atmospheric response to an idealized midlatitude SST front is explored here with the nonhydrostatic Weather Research and Forecasting (WRF) Model, version 3.3.1 ( Skamarock et al. 2008 ). WRF has been used to

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M. Oltmanns, F. Straneo, H. Seo, and G. W. K. Moore

1. Introduction Downslope winds in southeast Greenland can reach hurricane intensity, posing a threat to the local population ( Rasmussen 1989 ; Born and Böcher 2000 ; Klein and Heinemann 2002 ; Heinemann and Klein 2002 ; Mernild et al. 2008 ). They are especially pronounced within the valley of Ammassalik, where the flow is funneled by the topography ( Figs. 1 and 5 ). Using the European Centre for Medium-Range Weather Forecasts (ECMWF) interim reanalysis (ERA-I), Oltmanns et al. (2014

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M. A. Kuester, M. J. Alexander, and E. A. Ray

sampling rates. In this paper, regional and local analysis tools are used to investigate wave sources, properties, and behavior in the lower stratosphere above a tropical cyclone environment. Simulations of Humberto are developed using the fifth-generation Pennsylvania State University –National Center for Atmospheric Research (PSU–NCAR) Mesoscale Model (MM5). Humberto was observed in September 2001 during the fourth field campaign in the National Aeronautics and Space Administration’s (NASA

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Yefim L. Kogan and Alexei Belochitski

, employs many bins to discretize drop size distributions (DSDs), which evolve unconstrained according to microphysical processes of condensation/evaporation, coalescence, gravitational sedimentation, etc. The explicit microphysics approach is computationally expensive, but it is also limited to high-resolution models, as the coarse spatial grid of mesoscale and large-scale models does not allow prediction of the local supersaturation needed for calculation of drop condensational growth. The

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Alexander D. Schenkman, Ming Xue, and Alan Shapiro

upright, leading to more intense stretching of low-level vorticity. This result has recently been confirmed in a study by Schenkman et al. (2011a , hereafter S11a) , wherein real-data experiments that more effectively analyzed low-level shear forecasted stronger, longer-lived mesovortices. The dynamical link between mesovortices and tornadoes remains relatively unexplored. To the authors’ knowledge, no study has examined a case with sufficient resolution (either observationally or numerically) to

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M. Virman, M. Bister, V. A. Sinclair, J. Räisänen, and H. Järvinen

1. Introduction The majority of precipitation over tropical oceans is associated with mesoscale convective systems (MCSs; Rickenbach and Rutledge 1998 ), which produce both stratiform and convective precipitation (e.g., Houze 2018 ). The vertical heating profile associated with MCSs over the moistest regions of tropical oceans has been shown to be positive at all altitudes with its maximum in the upper troposphere (e.g., Houze 1982 ). The heating associated with MCSs strongly influences the

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Jannik Wilhelm, T. R. Akylas, Gergely Bölöni, Junhong Wei, Bruno Ribstein, Rupert Klein, and Ulrich Achatz

atmospheric applications is the second (hydrostatic) limit, for which the mesoscale-wave impact is the strongest. For instance, taking ( H m , L m ) = (1, 100) km and f / N * = 10 −2 , from (20) it is then found that ( H w , L w ) = (0.1, 1) km. Notably, this scale estimate is in good agreement with present-day local-area weather-forecast-code mesh distances (see section 1 ). For later reference, Table 1 provides an overview of the scales deduced in this section. It is worth noting that the

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