Projected Snow Cover Reductions and Mid-latitude Cyclone Responses in the North American Great Plains, 1986 - 2005

Extratropical cyclones are responsible for major weather events and trends in the
mid-latitudes and preferentially develop in regions of enhanced cyclogenesis and proceed
along climatological storm tracks. It has been shown that terrestrial snow cover exerts
considerable influence on atmospheric baroclinicity which is largely responsible for the
aforementioned cyclogeneses and storm tracks. Research about the effect which terrestrial
snow cover exerts on cyclones' intensities, trajectories, and precipitation characteristics
is limited but indicates a robust relationship with these factors. Many examinations of
climate model projections have generally shown a poleward shift in storm tracks by the late
21st century though none have determined the degree to which the coincident poleward shift
in snow extent is responsible. A method of imposing 10th, 50th, and 90th percentile values of snow retreat between the
late 20th and 21st centuries as projected by 14 models of the Coupled Model Intercomparison
Project Phase Five (CMIP5) is used to alter 20 historical cold season cyclones which tracked
over or adjacent to the North American Great Plains. Simulations by the Advanced Research
version of the Weather Research and Forecast Model (WRF-ARW) are initialized at 0 to 4 days
prior to cyclogenesis. Including control and sensitivity testing wherein snow is unaltered
or removed entirely, each cyclone case is simulated 25 times for a total of 500
simulations.