A 30-year climatology of lake-effect snow events in Indiana, including an analysis of upstream sounding variables as Predictors
Although it is difficult to distinguish between heavy and moderate events, there is a demonstrable dependence of snowfall on upstream parameters from the sounding at Green Bay, Wisconsin. The best sounding predictors are 850 hPa wind direction and low-level instability (or ΔT), with the heaviest snowfall cases typically characterized by a long fetch across Lake Michigan and moderate to strong instability. Upstream inversion strength behaves as a limiting factor, with strong inversions inhibiting snowfall. The inversion height, however, has a very weak relationship with snowfall; this is likely due to the substantial boundary layer modification resulting from flow over the lake. Other sounding parameters, including relative humidity and wind shear, have only minor relationships to snowfall.