Noteworthy Cool-Season Extreme Weather Events over Central and Eastern North America Associated with Strong Extratropical Cyclones Ph.D. Dissertation Prospectus Alicia M. Bentley Department of Atmospheric and Environmental Sciences University at Albany, State University of New York ABSTRACT Extratropical cyclones (ECs), which form in response to a combination of baroclinic, diabatic, and barotropic processes, play a major role in determining the dayto-day weather conditions in the midlatitudes during the cool season. Particularly strong ECs forming over and traversing densely populated regions of central and eastern North America have the potential to lead to noteworthy cool-season extreme weather events (EWEs), defined here as a category of high-impact weather events that are societally disruptive, geographically widespread, exceptionally prolonged, and climatologically infrequent. The opportunity to investigate the frequency, evolution, and predictability of strong ECs leading to noteworthy cool-season EWEs over central and eastern North America motivates this study. The interannual and intraseasonal variability associated with the location and frequency of strong ECs leading to noteworthy cool-season EWEs over central and eastern North America will be documented in the proposed study by constructing a 1979– present climatology. The relative contributions of baroclinic, diabatic, and barotropic processes will be quantified during the evolution of strong ECs included in the 1979– present climatology in order to determine the combinations of processes most likely to yield strong ECs. A cyclone-relative composite analysis will be performed on clusters of strong ECs included in the 1979–present climatology that are governed by similar combinations of baroclinic, diabatic, and barotropic processes in order to document the structure, motion, and evolution of the most prominent upper- and lower-tropospheric features associated with the formation and motion of the strong ECs. The relationship between the skill with which strong ECs included in the 1979–present climatology are forecast and the combinations of baroclinic, diabatic, and barotropic processes associated with their formation will also be explored.