Dear Tom, On Jim Ramsey's WGN-TV weathercast a few years ago, he showed satellite photographs in which cloud cover almost exactly matched the shape of the Great Lakes. Other areas were clear but clouds over the lakes matched the shape of the lakes. I found it very interesting. Cold weather effect? Sharon Hrycewicz, Batavia Dear Sharon, Cold-weather effect it was. Very cold air over relatively warm water stimulates the development of cumulus and stratocumulus clouds over the water. It's practically a daily occurrence in the Great Lakes region during the winter. Usually, though, brisk winds constantly transport those clouds downwind and over land. Sometimes, as in the situation that caught your attention, minimal air motion allows the clouds to hover right where they form: over the water. ...
Anytime
