It doesn’t snow much in the upper Midwest in recent winters. Ski resorts are suffering. and so are the Great Lakes.
Most environmental researchers say that low precipitation, mild winters and high evaporation, due largely to a lack of heavy ice covers to shield cold lake waters from the warmer air above, are depleting the lakes. The Great Lakes follow a natural cycle, their levels rising in the spring, peaking in the summer and reaching a low in the winter, as the evaporation rate rises.
In the past two years, evaporation has been higher than average, and not enough rain and snow have fallen in the upper lakes — Superior, Michigan and Huron — which supply water to the lower lakes, to restore the system to its normal levels, said Keith Kompoltowicz, a meteorologist at the Corps of Engineers’ office in Detroit, which monitors water levels in the lakes. “Mother Nature is largely the driving force on what the water levels are, and it plays a large role in what we project water levels to be,” Mr. Kompoltowicz said.