The Lake Effect of the Great Salt Lake: Overview and Forecast Problems

Abstract

A lake-effect snow phenomenon along the shore of the Great Salt Lake (GSL) in Utah is documented and related to a similar, well-documented lake effect along the shores of the Great Lakes. Twenty-eight cases of GSL lake-effect snowfall are examined for common parameters that can be used to forecast the occurrence of the lake effect and the location of the heaviest snowfall. Each of the cases produced at least 4 in. (10 cm) of snow at some point in the Salt Lake Valley, and nine of them produced over a foot (30 cm) of snow. Upper-air data at 700 mb provide information useful in forecasting both the occurrence of the lake effect and the location of the heaviest snowfall. A temperature difference of at least 17°C between the GSL and 700 mb is common in the heaviest snowfall cases. A method for real-time diagnosis of the temperature of the GSL is discussed. The 700-mb wind direction is useful for predicting the location of heaviest snowfall. The 18 October 1984 case is highlighted as an example of a GSL lake-effect storm and as an example of the forecast problems presented by the GSL lake effect.