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Robert D. Sharman, Yubao Liu, Rong-Shyang Sheu, Thomas T. Warner, Daran L. Rife, James F. Bowers, Charles A. Clough, and Edward E. Ellison

Abstract

Output from the Army Test and Evaluation Command’s Four-Dimensional Weather System’s mesoscale model is used to drive secondary-applications models to produce forecasts of quantities of importance for daily decision making at U.S. Army test ranges. Examples of three specific applications—a sound propagation model, a missile trajectory model, and a transport and diffusion model—are given, along with accuracy assessments using cases in which observational data are available for verification. Ensembles of application model forecasts are used to derive probabilities of exceedance of quantities that can be used to help range test directors to make test go–no-go decisions. The ensembles can be based on multiple meteorological forecast runs or on spatial ensembles derived from different soundings extracted from a single meteorological forecast. In most cases, the accuracies of the secondary-application forecasts are sufficient to meet operational needs at the test ranges.

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Yubao Liu, Thomas T. Warner, Elford G. Astling, James F. Bowers, Christopher A. Davis, Scott F. Halvorson, Daran L. Rife, Rong-Shyang Sheu, Scott P. Swerdlin, and Mei Xu

Abstract

This study builds upon previous efforts to document the performance of the U.S. Army Test and Evaluation Command’s Four-Dimensional Weather Modeling System using conventional metrics. Winds, temperature, and specific humidity were verified for almost 15 000 forecasts at five U.S. Army test ranges using near-surface mesonet data. The primary objective was to use conventional metrics to characterize the degree to which forecast accuracy varies from range to range, within the diurnal cycle, with elapsed forecast time, and among the seasons. It was found that there are large interrange differences in forecast error, with larger errors typically associated with the ranges located near complex orography. Similarly, significant variations in accuracy were noted for different times in the diurnal cycle, but the diurnal dependency varied greatly among the ranges. Factor of 2 differences in accuracy were also found across the seasons.

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Jason C. Knievel, Yubao Liu, Thomas M. Hopson, Justin S. Shaw, Scott F. Halvorson, Henry H. Fisher, Gregory Roux, Rong-Shyang Sheu, Linlin Pan, Wanli Wu, Joshua P. Hacker, Erik Vernon, Frank W. Gallagher III, and John C. Pace

Abstract

Since 2007, meteorologists of the U.S. Army Test and Evaluation Command (ATEC) at Dugway Proving Ground (DPG), Utah, have relied on a mesoscale ensemble prediction system (EPS) known as the Ensemble Four-Dimensional Weather System (E-4DWX). This article describes E-4DWX and the innovative way in which it is calibrated, how it performs, why it was developed, and how meteorologists at DPG use it. E-4DWX has 30 operational members, each configured to produce forecasts of 48 h every 6 h on a 272-processor high performance computer (HPC) at DPG. The ensemble’s members differ from one another in initial-, lateral-, and lower-boundary conditions; in methods of data assimilation; and in physical parameterizations. The predictive core of all members is the Advanced Research core of the Weather Research and Forecasting (WRF) Model. Numerical predictions of the most useful near-surface variables are dynamically calibrated through algorithms that combine logistic regression and quantile regression, generating statistically realistic probabilistic depictions of the atmosphere’s future state at DPG’s observing sites. Army meteorologists view E-4DWX’s output via customized figures posted to a restricted website. Some of these figures summarize collective results—for example, through means, standard deviations, or fractions of the ensemble exceeding thresholds. Other figures show each forecast, individually or grouped—for example, through spaghetti diagrams and time series. This article presents examples of each type of figure.

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Yubao Liu, Thomas T. Warner, James F. Bowers, Laurie P. Carson, Fei Chen, Charles A. Clough, Christopher A. Davis, Craig H. Egeland, Scott F. Halvorson, Terrence W. Huck Jr., Leo Lachapelle, Robert E. Malone, Daran L. Rife, Rong-Shyang Sheu, Scott P. Swerdlin, and Dean S. Weingarten

Abstract

Given the rapid increase in the use of operational mesoscale models to satisfy different specialized needs, it is important for the community to share ideas and solutions for meeting the many associated challenges that encompass science, technology, education, and training. As a contribution toward this objective, this paper begins a series that reports on the characteristics and performance of an operational mesogamma-scale weather analysis and forecasting system that has been developed for use by the U.S. Army Test and Evaluation Command. During the more than five years that this four-dimensional weather system has been in use at seven U.S. Army test ranges, valuable experience has been gained about the production and effective use of high-resolution model products for satisfying a variety of needs. This paper serves as a foundation for the rest of the papers in the series by describing the operational requirements for the system, the data assimilation and forecasting system characteristics, and the forecaster training that is required for the finescale products to be used effectively.

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Thomas Warner, Paul Benda, Scott Swerdlin, Jason Knievel, Edward Argenta, Bryan Aronian, Ben Balsley, James Bowers, Roger Carter, Pamela Clark, Kirk Clawson, Jeff Copeland, Andrew Crook, Rod Frehlich, Michael Jensen, Yubao Liu, Shane Mayor, Yannick Meillier, Bruce Morley, Robert Sharman, Scott Spuler, Donald Storwold, Juanzhen Sun, Jeffrey Weil, Mei Xu, AL Yates, and Ying Zhang

The Pentagon, and its 25,000+ occupants, represents a likely target for a future terrorist attack using chemical, biological, or radiological material released into the atmosphere. Motivated by this, a building-protection system, called Pentagon Shield, is being developed and deployed by a number of government, academic, and private organizations. The system consists of a variety of data-assimilation and forecast models that resolve processes from the mesoscale to the city scale to the building scale, and assimilate meteorological and contaminant data that are measured by remote and in situ sensors. This paper reports on a field program that took place in 2004 in the area of the Pentagon, where the aim was to provide meteorological data and concentration data from tracer releases, and to support the development and evaluation of the system. In particular, the results of the field program are being used to improve our understanding of urban meteorological processes, verify the overall effectiveness of the operational building protection system, and verify the skill of the component meteorological, and transport and dispersion, modeling systems. Based on the experience gained in this project, it will be more straightforward to develop similar systems to protect other high-profile facilities against the accidental or intentional release of hazardous material into the atmosphere.

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