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John G. W. Kelley, Joseph M. Russo, J. Ronald Eyton, and Toby N. Carlson

A technique called Model Output Enhancement (MOE) has been developed for the generation and display of mesoscale weather forecasts. The MOE technique derives mesoscale or high-resolution (order of 1 km) weather forecasts from synoptic-scale numerical weather-prediction models by modifying model output with geophysical and land-cover data. Mesoscale forecasts generated by the MOE technique are displayed as color-class maps overlaid on perspective plots of terrain. The MOE technique has been demonstrated in the generation of mesoscale maximum-temperature and minimum-temperature forecasts for case-study days of clear-sky conditions over the Commonwealth of Pennsylvania. The generated forecasts were evaluated using data from selected climatological stations.

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Clifford Mass, Susan Joslyn, John Pyle, Patrick Tewson, Tilmann Gneiting, Adrian Raftery, Jeff Baars, J. M. Sloughter, David Jones, and Chris Fraley

This paper describes the University of Washington Probability Forecast (PROBCAST), a Web-based portal to probabilistic weather predictions over the Pacific Northwest. PROBCAST products are derived from the output of a mesoscale ensemble system run at the University of Washington, with the fields being postprocessed using Bayesian model averaging to produce sharp and reliable probabilistic predictions of temperature and precipitation. Based on research by University of Washington psychologists and human-interface specialists, a Web site has been constructed that allows for access to key elements of the probabilistic information produced by the system. The design approach of the PROBCAST system is explained in this paper as well as some of the challenges for future development. PROBCAST is intended to be a prototype for the kind of probabilistic forecast interface that could be used throughout the nation.

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Ian A. Renfrew, G. W. K. Moore, Teddy R. Holt, Simon W. Chang, and Peter Guest

This report discusses the design and implementation of a specialized forecasting system that was set up to support the observational component of the Labrador Sea Deep Convection Experiment. This ongoing experiment is a multidisciplinary program of observations, theory, and modeling aimed at improving our knowledge of the deep convection process in the ocean, and the air–sea interaction that forces it. The observational part of the program was centered around a cruise of the R/V Knorr during winter 1997, as well as several complementary meteorological research flights. To aid the planning of ship and aircraft operations a specially tailored mesoscale model was run over the Labrador Sea, with the model output postprocessed and transferred to a remote field base. The benefits of using a warm-start analysis cycle in the model are discussed. The utility of the forecasting system is illustrated through a description of the flight planning process for several cases. The forecasts proved to be invaluable both in ship operations and in putting the aircraft in the right place at the right time. In writing this narrative the authors hope to encourage the use of similar forecasting systems in the support of future field programs, something that is becoming increasingly possible with the rise in real-time numerical weather prediction.

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Clifford F. Mass and David Ovens

operational NOAA/NWS Global Forecast System (GFS) model grids. The model evolution for this event was highly realistic, with the simulation closely following the observed synoptic and mesoscale development. For example, the observed and simulated vertical soundings at Reno, Nevada during the downslope wind period (0000 UTC 8 November to 0000 UTC 9 November) were very similar; both developed a midlevel stable layer that descended in time, with similar evolution in horizontal winds and moisture in the lower

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Someshwar Das, S. V. Singh, E. N. Rajagopal, and Robert Gall

Severe weather has a more calamitous effect in the mountainous region because the terrain is complex and the economy is poorly developed and fragile. Such weather systems occurring on a small spatiotemporal scale invite application of models with fine-grid resolution and observations from radars and satellites besides the conventional observations for forecasting and disaster mitigation.

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Dmitry Kiktev, Paul Joe, George A. Isaac, Andrea Montani, Inger-Lise Frogner, Pertti Nurmi, Benedikt Bica, Jason Milbrandt, Michael Tsyrulnikov, Elena Astakhova, Anastasia Bundel, Stéphane Bélair, Matthew Pyle, Anatoly Muravyev, Gdaly Rivin, Inna Rozinkina, Tiziana Paccagnella, Yong Wang, Janti Reid, Thomas Nipen, and Kwang-Deuk Ahn

alpine winter weather observations and forecasts; development of nowcasting systems, as well as mesoscale deterministic and ensemble forecasting systems, for winter weather conditions in complex terrain with a focus on HIW phenomena; operational meteorological support of the Games; improvement of our understanding of regional HIW phenomena physics/mechanisms; and evaluation of the developed forecasting systems and assessing the benefits of their use (verification and societal impacts). A list of

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Mark J Rodwell, Linus Magnusson, Peter Bauer, Peter Bechtold, Massimo Bonavita, Carla Cardinali, Michail Diamantakis, Paul Earnshaw, Antonio Garcia-Mendez, Lars Isaksen, Erland Källén, Daniel Klocke, Philippe Lopez, Tony McNally, Anders Persson, Fernando Prates, and Nils Wedi

is indicated with bold colors. Throughout this article, the analyzed CAPE is actually a 6-h forecast, since this is what is archived. CAPE is computed for several parcel ascents, from the surface and higher up, and the maximum value is taken. Grazzini and Isaksen (2002) linked busts to mesoscale convective systems (MCSs) over the United States, particularly around the Great Lakes region. Figure 4b shows the convective available potential energy (CAPE) in the mean initial conditions of the bust

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William J. Shaw, Larry K. Berg, Joel Cline, Caroline Draxl, Irina Djalalova, Eric P. Grimit, Julie K. Lundquist, Melinda Marquis, Jim McCaa, Joseph B. Olson, Chitra Sivaraman, Justin Sharp, and James M. Wilczak

initiated a 4-yr study, the Second Wind Forecast Improvement Project (WFIP2), to improve the representation of boundary layer physics and related processes in mesoscale models for better wind and wind power forecasts in complex terrain. WFIP2 was an interagency, public–private partnership under the Atmosphere to Electrons (A2e) initiative (see the “A2e initiative” sidebar) comprising DOE and National Oceanographic and Atmospheric Administration (NOAA) laboratories as well as the wind industry and

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Sharanya J. Majumdar

advances include the addition of moisture, with applications to mesoscale weather. All of the techniques to date employ either adjoint methods or ensemble forecasts. Some are based on the direct sensitivity of a response function or forecast metric (e.g., total energy within the verification region) to observations or changes to the analysis, whereas others make quantitative predictions of the effect of assimilating targeted observations. Hybrids of certain techniques have been proposed, such as the

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Jordan G. Powers, Kevin W. Manning, David H. Bromwich, John J. Cassano, and Arthur M. Cayette

AMPS, a real-time mesoscale modeling system, has provided a decade of service for scientific and logistical needs and has helped advance polar numerical weather prediction as well as understanding of Antarctica. With 2011 marking the 100th anniversary of Roald Amundsen's being the first to reach the South Pole, the Antarctic endeavor has come a long way. The capabilities to support it have as well. In the critical area of weather forecasting, the Antarctic Mesoscale Prediction System (AMPS) has

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