Lake effect snow is highly localized snowfall, sometimes
intense, that forms downwind of large bodies of water such as
the Great Lakes. They usually take the shape of narrow bands and
can produce significant snow accumulation within very short time
periods. As shown on the map below, the Great Lakes have a
tremendous influence on the amount of snowfall that falls
downwind of their location. On the map below, 100 cm equals
about 40 inches. Lake effect snow actually requires a specific
set of conditions involving the atmosphere, land, and water
surface. There are 5 primary ingredients the play a role in the
formation of lake effect snow. 1. Cold air over a relatively
warmer body of water - this results in instability in the
atmosphere, and creates a situation where heat and moisture is
lifted from the water and transported by the wind downstream.
The warm moist air rises and snow showers and squalls form.
Typically a temperature difference of 13 degrees C or 24 degrees
F between the lake water surface and the a