Nasty. Unpredictable. The worst part about living by Lake Erie. That is, of course, unless you're a weather forecaster. "Lake-effect snow is an exciting weather phenomenon that occurs in only a few locations around the world," offers Kirk Lombardy, a meteorologist with Cleveland's National Weather Service. "The Great Lakes happens to be one of them." Sure, it's not so nifty when you're shoveling the fluffy stuff off your driveway, but the science behind it is still pretty cool. (Or not.)
A mass of cold, Arctic air — traditionally from the west or northwest — moves across the warmer waters of Lake Erie.
The temperature difference causes clouds to form quickly over the lake. "It's like what you see in a steam room," Lombardy explains. "When you have a lot of moisture in the air that is forced to cool down, you see a cloud develop."
Frigid air can hold very little moisture, so it begins to fall as snow. Moving inland, the warmer air rises and is cooled again higher in the atmosphere. Because it's produced so rapidly, lake-effect snow is usually lighter and fluffier than other snowfalls.