What is Lake Effect Snow?

Source: GLISA/NOAA | University of Michigan

Lake Effect Snow events are snowstorms that form on the downwind side of a body of water with a concave coastline. The map to the right (above) shows some locations where lake effect snowstorms often occur. They are not just confined to the Great Lakes regions. Similar phenomena are:

• Lake Effect (Great Salt Lake)
• Bay Effect (Chesapeake Bay, Cape Cod Bay)
• Ocean Effect (Gulf Stream)

These events are very localized, extending from just a couple of miles up to 30 miles and only a few miles wide. In the most extreme cases, the bands can extend 100 miles inland and about 30 miles wide.