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Skylar S. Williams, Timothy J. Wagner, and Ralph A. Petersen

that WVSS are compatible and agree well with operational radiosonde observations over the CONUS throughout the entire troposphere. WVSS observations have already been found to be impactful for forecasters and NWP. Hoover et al. (2017) found the assimilation of AMDAR moisture observations improved forecasts and the observation-minus-background bias and RMSE was lowered in the warm season experiment and James and Benjamin (2017) found that aircraft water vapor observations from WVSS were

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Seppo Pulkkinen, V. Chandrasekar, and Ari-Matti Harri

1. Introduction Flash floods can cause significant property damage and loss of lives. Therefore, nowcasts (short-range forecasts) of severe rainfall causing such events are highly valuable for the society. Providing early warnings is especially important in densely populated urban areas. Weather radars are ideal for this purpose because of their high spatial and temporal resolution, for which the typical ranges in operational radar networks are 1–5 km and 5–15 min. Thus, the use of weather

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Kun Tao and Ana P. Barros

in general, we focus here on summertime convective rainfall, which is characterized by high space–time variability and thus poses an additional challenge because of limited temporal sampling (i.e., satellite revisit times). In addition, the operational skill scores for areal QPE and quantitative precipitation forecasting (QPF) for this type of rainfall remain very low and have yet to beat persistence at the time scales and for rainfall amounts that matter for hazard warning in practice (e

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Pekka J. Rossi, Vesa Hasu, Kalle Halmevaara, Antti Mäkelä, Jarmo Koistinen, and Heikki Pohjola

infrastructure makes it possible to develop information sources of completely new kinds and methods for protecting us against severe weather hazards. For example, in nowcasting, the knowledge of hazardous events caused by a certain convective storm would help in warning people. Typically, severe weather warnings are part of operational weather services. Quite often, meteorologists take care of general weather forecasts and warnings. In some cases, depending on local resources and susceptibility to severe

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M. K. Rama Varma Raja, Seth I. Gutman, James G. Yoe, Larry M. McMillin, and Jiang Zhao

vapor retrievals in operational weather forecast models. GPS observation errors have been quantified ( Smith et al. 2007 ), and these observations are currently being assimilated into two operational weather models running at the National Centers for Environmental Prediction (NCEP), the Rapid Update Cycle (RUC) and the North American Mesoscale (NAM) models. In this investigation, GPS IPW retrievals represent a volume-averaged estimate of IPW over the region of the atmosphere covered by all GPS

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Timothy J. Wagner and Jessica M. Kleiss

Assessment Report (AR5), which notes that they remain the single greatest source of uncertainty in estimating the magnitude of changes to the energy budget of the planet ( Boucher et al. 2013 ). It is readily apparent that the accuracy of the simulations performed in weather and climate models fundamentally depends on the ability to properly model clouds and their impacts. While certain cloud species are large enough to be resolved by the current generation of operational weather forecast models, other

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Rod Frehlich

1. Introduction Improved short-term forecasts of winds from an operational numerical weather prediction (NWP) system would benefit current wind farms ( Mueller et al. 2003 ; Benjamin et al. 2004 ; Saxen et al. 2008 ; Hannon et al. 2008 ; Benjamin et al. 2010 ; Marquis et al. 2011 ). The output power of a wind turbine is determined by the wind profile over the altitude range of the turbine blades. Using just the wind speed at hub height provides an acceptable calculation of power production

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G. R. Halliwell Jr., A. Srinivasan, V. Kourafalou, H. Yang, D. Willey, M. Le Hénaff, and R. Atlas

-resolution coastal models nested within it that will all employ realistic high-frequency river runoff ( Schiller et al. 2011 ) for the purpose of evaluating coastal ocean observing systems. c. Evaluation of the T-SIS DA methodology Before conducting the OSSE system evaluation, the performance of the new T-SIS DA methodology is analyzed in comparison to two operational HYCOM Navy Coupled Ocean Data Assimilation (NCODA) ocean analysis products produced by the U.S. Navy using the operational HYCOM nowcast–forecast

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Emmanouil N. Anagnostou and Witold F. Krajewski

observations span the period of two months: 3 August–30 September 1995. During this period, Hurricane Erin and Tropical Storm Jerry passed over the area. The algorithm-generated rain products are compared against the operational WSR-88D Precipitation Processing Subsystem (PPS) estimates ( Fulton et al. 1998 ). These comparisons are used to demonstrate relative improvements coming from the various components of the algorithm with respect to the operational PPS. Improvement is quantified in terms of the

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Philipp M. Kostka, Martin Weissmann, Robert Buras, Bernhard Mayer, and Olaf Stiller

. Meteorological model and data The forecast fields used to simulate synthetic satellite images are produced by the COSMO community model ( Baldauf et al. 2011 ). The COSMO model has been used for operational numerical weather prediction at DWD since 1999. The convection-permitting model configuration COSMO-DE has been operational since April 2007. The model domain has a horizontal grid spacing of 2.8 km and consists of 421 × 461 grid points. The area covers Germany, as well as Switzerland, Austria, and parts

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