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Xu Zhang, Yuhua Yang, Baode Chen, and Wei Huang

1. Introduction As computational power has increased, limited-area operational numerical weather prediction (NWP) models with horizontal grid spacing of 1–10 km for short-range weather forecasting are introduced in many operational forecast centers. At such scales, many models have typically been configured without using a convection parameterization scheme (CPS). However, such a configuration generally leads to subgrid convective updrafts being forced on the grid scale and precipitation with

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Arun Chawla, Hendrik L. Tolman, Vera Gerald, Deanna Spindler, Todd Spindler, Jose-Henrique G. M. Alves, Degui Cao, Jeffrey L. Hanson, and Eve-Marie Devaliere

1. Introduction At operational centers like the National Centers for Environmental Prediction (NCEP), numerical models are used to obtain initial forecast guidance that are then used by forecasters who, after accounting for known model errors, issue official forecasts. From a forecaster's point of view, a valuable model guidance system needs to be (a) as close as possible to the ground truth and (b) delivered in a timely fashion so that it can be used to develop a forecast. Thus, considerable

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Joshua H. Cossuth, Richard D. Knabb, Daniel P. Brown, and Robert E. Hart

). Tropical cyclogenesis has therefore become the subject of extensive research. Further, the operational community has begun to enhance their public products, including forecasts of TC formation, due to great user interest in that information. This paper describes historical data and analyses and their use in producing a forecasting tool that can assist operational centers in making present-day genesis forecasts and in assessing the skill of new and future forecast capabilities arising from ongoing

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Adam J. Clark, William A. Gallus Jr., and Morris L. Weisman

of forecasts as perceived by human forecasters. The purpose of this study is to demonstrate the usefulness of a neighborhood-based equitable threat score (ETS; Schaefer 1990 ) to compare precipitation forecasts from experimental convection-allowing Weather Research and Forecasting Model (WRF; Skamarock et al. 2005 ) simulations conducted during April–July 2004–08 by the National Center for Atmospheric Research (NCAR) to operational North American Mesoscale (NAM; Janjić 2003 ) model forecasts

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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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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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Amanda Burke, Nathan Snook, David John Gagne II, Sarah McCorkle, and Amy McGovern

NOAA’s Hazardous Weather Testbed (HWT) Spring Forecasting Experiment (SFE). For example, during the 2010 HWT SFE operational forecasters subjectively indicated that the CAM guidance improved convection forecasts, compared to traditional convective-parameterizing schemes ( Clark et al. 2012 ). Also, Gallo et al. (2017) noted that CAMs played an important role in reliable short-term forecasts, especially hourly forecasts, during the 2015 HWT SFE. For day-ahead forecasts (12–36-h lead time), CAM

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Amanda Burke, Nathan Snook, David John Gagne II, Sarah McCorkle, and Amy McGovern

NOAA’s Hazardous Weather Testbed (HWT) Spring Forecasting Experiment (SFE). For example, during the 2010 HWT SFE operational forecasters subjectively indicated that the CAM guidance improved convection forecasts, compared to traditional convective-parameterizing schemes ( Clark et al. 2012 ). Also, Gallo et al. (2017) noted that CAMs played an important role in reliable short-term forecasts, especially hourly forecasts, during the 2015 HWT SFE. For day-ahead forecasts (12–36-h lead time), CAM

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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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Vijay Tallapragada, Chanh Kieu, Samuel Trahan, Zhan Zhang, Qingfu Liu, Weiguo Wang, Mingjing Tong, Banglin Zhang, and Brian Strahl

mi at 1–5-day forecast lead times, respectively ( Evans and Falvey 2013 ), indicating about 20% larger errors in the WPAC compared to NATL. Given the high degree of uncertainty of TC forecasts in this ocean basin, consensus of multiple models or ensemble forecasts is an optimal choice for improving the operational forecast skill as these ensemble approaches could take into account the strengths and weaknesses of each individual model (e.g., Evans and Falvey 2013 ). In an attempt to support

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