Lake-effect snow explained

It's an incredible weather phenomenon! When conditions are just right, communities around the Great Lakes can pick up inches, even feet, of snow within hours. Let's learn more about lake effect snow.

Every year, the U.S. Snowbelt is graced with very heavy snow thanks to cold air moving across the Great Lakes during late autumn and winter - and we have it in the forecast later this week. But how exactly does this work?

Lake effect snow is only possible when the lake’s water temperatures are much warmer than the air flowing over them. This means the lakes have very little to no ice on them, and the air moving across the bodies of water is likely from the north or northwest, which is much colder than the air to the south.

Snow clouds form and grow when cold winds kick up and flow across the warmer body of water. The elevation of the land downwind from the body of water is important. The more these clouds rise, thanks to the increasing land elevation, the better the instability for snowfall to occur.

One final detail needed for the lake-effect snow to accumulate is that temperatures on land must be near or below freezing for any snow to pile up. The heaviest bands can produce 2 to 3 inches or more of snow per hour, sometimes causing white-out conditions and dangerous slick roadways.