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Tsing-Chang Chen, Jenq-Dar Tsay, and Eugene S. Takle

sea breeze. (b) Two tracks of surface stations connected by red lines along the Tanshui (1–6) and Keelung (7–12) River valleys. Surface winds measured at 1200 LST 18 Aug 2005 are displayed as an example to illustrate the sea breezes along these two river valleys, labeled with red lines. The elevation scale of the orography is also added to each panel. To properly manage the water supply, to mitigate traffic hazards, and to reduce air pollution in the Taipei basin, day-ahead forecasts for the

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Ariel F. Stein, Glenn D. Rolph, Roland R. Draxler, Barbara Stunder, and Mark Ruminski

1. Introduction Rolph et al. (2009) introduced the National Oceanic and Atmospheric Administration’s (NOAA) Smoke Forecasting System (SFS), a smoke forecasting tool within the National Weather Service’s (NWS) National Air Quality Forecast Capability (NAQFC) ( Stockwell et al. 2002 ). The SFS, composed of the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) dispersion model ( Draxler and Hess 1997 , 1998 ), the BlueSky framework emission processing ( Larkin et al. 2009 ), and

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David R. Novak, David R. Bright, and Michael J. Brennan

1. Introduction Uncertainty is a fundamental characteristic of hydrometeorological (hydrologic, weather, and seasonal climate) prediction, and is a consequence of the inherent chaotic nature of the atmosphere, inadequate observations, and numerical weather prediction (NWP) deficiencies ( NRC 2006 ). Thus, the assessment and communication of uncertainty is an inherent part of any forecast process. The assessment of uncertainty in modern operational forecasting has largely relied on the use of

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André April

1. Introduction In Canadian waters, forecasting events such as the onset of ice breakup or a marine area being considered open water or bergy water is important to the shipping trade and the Coast Guard for ship routing and icebreaking plans. Bergy water is an area of freely navigable water in which ice of glacier origin is present. Other ice types may be present, although the total concentration of all other ice is less than 1/10. Open water is an area of freely navigable water in which ice is

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Philip A. Lutzak

radar imagery, depending upon the size of the cloud particles (or insects carried aloft), the amplitude of the waves, and their distance from the radar site. Undular bores produce discrete, measureable changes in the lower atmosphere and at the surface, with a notable veering of the wind, rise in barometric pressure, and without decrease in temperature ( Locatelli et al. 1998 ); this allows researchers to identify their passage and, as will be shown, can also be used to forecast their occurrence

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Matthew J. Onderlinde and Henry E. Fuelberg

produced 37 tornadoes ( Vescio et al. 1996 ). Numerous studies have found a strong preference for tornadoes to occur in the right-front quadrant relative to storm motion or relative to true north (these two quadrants often are similar) ( Sadowski 1962 ; Smith 1965 ; Pearson and Sadowski 1965 ; Hill et al. 1966 ; Novlan and Gray 1974 ; Gentry 1983 ; McCaul 1991 ; Verbout et al. 2007 ; Schultz and Cecil 2009 ). When attempting to forecast TC-related severe local storms, McCaul (1991) suggested

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Lori Drake

1. Introduction Warning members of the public about impending tropical cyclone (TC) threats to their communities necessarily involves the communication of TC descriptions and forecasts, and their associated uncertainties, based in science, to audiences composed primarily of nonscientists. Since the data cannot be communicated in raw form outside the discipline, what is actually disseminated is information about what meteorologists know—and what they do not know—about the current and projected

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Clark Evans, Donald F. Van Dyke, and Todd Lericos

1. Introduction Meteorological ensembles owe substantial motivation to the findings of Lorenz (1963) , who demonstrated that a small change in the initial representation of the atmospheric state can result in comparatively large forecast differences between any two otherwise identical forecasts. Though the precise methods of doing so vary from one ensemble prediction system to another, modern ensembles attempt to quantify part or all of the range of plausible forecast outcomes that may be

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Chermelle Engel and Elizabeth E. Ebert

1. Introduction Public weather forecast practices change with the quality and amount of information and tools available. In Australia, public weather forecasts have evolved over the decades from short-term forecasts (around 24 h ahead), based on locally observed information ( Persson 2005 ; Persson and Grazzini 2007 ), to forecasts with lead times out to 8 days, which are strongly guided by numerical weather prediction (NWP) model forecasts. As NWP models improve, public weather forecasting

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William S. Lamberson, Ryan D. Torn, Lance F. Bosart, and Linus Magnusson

1. Introduction The last 30 years have been characterized by a significant improvement in the quality of medium-range (3–10 day) forecasts of midlatitude weather systems. Presently, 6-day forecasts issued by the European Centre for Medium-Range Weather Forecasts (ECMWF) for the Northern Hemisphere extratropics are as accurate as 5-day forecasts issued in the early 2000s, 4-day forecasts issued in the mid-1990s, and 3-day forecasts issued in the early 1980s ( Richardson et al. 2013 ). These

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