Frequency and Influence of Elevated Mixed Layers Upwind of the Great Lakes

Lake effect storms have significant impacts on over 30 million people living in the Great Lakes region
every year. Conditions on the upwind side of a lake play a large role in the development of lake effect
storms that produce snow in communities located on downwind shores. Little research has been done
on upwind conditions and how they influence lake effect snowfall. Elevated mixed layers are believed to
increase lake effect snowfall. We analyzed several atmospheric variables from sounding data taken in
Detroit, Michigan as a way of determining the presence of elevated mixed layers on the upwind side of
Lake Erie during the OWLeS campaign (December 2013 through January 2014). Some of these variables
include the 𝜃𝑒 and 𝜃 gradients and relative humidity. We define an elevated mixed layer as a layer above
the surface with nearly constant 𝜃𝑒. We also analyzed the relationship between the presence of
elevated mixed layers and boundary layer presence, boundary layer depth, and cyclone presence. Our
findings suggest that elevated mixed layers occur more frequently than previously thought.