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.