Multiscale Analysis of the 7 December 1998 Great Salt Lake–Effect Snowstorm

Abstract

The large-scale and mesoscale structure of the Great Salt Lake?effect snowstorm of 7 December 1998 is examined using radar analyses, high-density surface observations, conventional meteorological data, and a simulation by the Pennsylvania State University?National Center for Atmospheric Research fifth generation Mesoscale Model (MM5). Environmental conditions during the event were characterized by a lake?700-hPa temperature difference of up to 22.5°C, a lake?land temperature difference as large as 10°C, and conditionally unstable low-level lapse rates. The primary snowband of the event formed along a land-breeze front near the west shoreline of the Great Salt Lake. The snowband then migrated eastward and merged with a weaker snowband as the land-breeze front moved eastward, offshore flow developed from the eastern shoreline, and low-level convergence developed near the midlake axis. Snowfall accumulations reached 36 cm and were heaviest in a narrow, 10-km-wide band that extended downstream from the southern shore of the Great Salt Lake. Thus, although the Great Salt Lake is relatively small in scale compared to the Great Lakes, it is capable of inducing thermally driven circulations and banded precipitation structures similar to those observed in lake-effect regions of the eastern United States and Canada.