Abstract
The processes responsible for the Great Salt Lake–effect snowstorm of 7 December 1998 are examined using a series of mesoscale model simulations. Localized surface sensible and latent heating are shown to destabilize the boundary layer over the Great Salt Lake (GSL) and to produce mesoscale pressure troughing, land-breeze circulations, and low-level convergence that lead to the development of the primary band of convective clouds and precipitation. Model diagnostics and sensitivity studies further illustrate that
moisture fluxes from the lake surface were necessary to fully develop the snowband;
the hypersaline composition of the GSL did, however, decrease moisture fluxes compared to a body of freshwater, resulting in a 17% reduction of snowfall;
latent heat release within the cloud and precipitation band intensified overlake pressure troughing, convergence, and precipitation;
orographic effects were not responsible for snowband generation, but they did affect the distribution and intensity of precipitation in regions where the snowband interacted with downstream terrain; and
surface roughness contrasts across the GSL shoreline did not play a primary role in forming the snowband.
Corresponding author address: Dr. Daryl J. Onton, Department of Meteorology, University of Utah, 135 South 1460 East Room 819, Salt Lake City, UT 84112-0110.
Email: djonton@met.utah.edu