at 4:16 PM by Pierce Larkin

What is Lake Effect Snow?

If you saw the post from Tyler Smith this morning, Buffalo is in the midst of an incredible lake effect snow storm. The NWS Buffalo is reporting that within the bands of snowfall, they are seeing snowfall rates up to 5″/hr, and totals of up to 70″ just south of Buffalo!

While these events seem very foreign and ridiculous to us, lake effect snow is not an uncommon visitor to communities along the coasts of the Great Lakes during winter. So how do these events work? Well, it all starts with the lakes themselves. In general, land and water have much different rates of temperature change as land is able to cool and warm faster than water is. During the winter months, the water is able to retain some of the warmth it gained during the warm summer months.

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The current lake temperatures for Lake Erie. Given that air temperatures are much lower in comparison, we are seeing an anomaly event with very high lake instability. (h/t  glerl.noaa.gov)

When cooler air masses move over the warm Great Lakes waters, and the winds align right, the stage is set for lake effect precipitation. The cooler air creates an unstable atmosphere that is favorable for bands to form and strengthen, and thus, drop heavy amounts of snowfall wherever they set up. It works a lot like this:

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A diagram showing how lake effect precipitation works. (h/t personal.psu.edu)

Because these are based upon the direction of the winds, and how long they prevail from that direction, they are often able to act much like thunderstorms that train in one spot and dump a lot of precipitation. And with the instability that forms with the temperature differences, thunder and lightning are often times observed within these bands. Lake effect snow bands are known to produce several multi-feet snowstorms every winter, and in 2002 a storm produced 127″ of snowfall in one storm! 

Lake effect snows are incredible events within meteorology, and while we see these snowfall totals and are astounded, the Great Lakes regions are relatively used to it by this point. For even more information on lake effect snowfall, check out the NWS in Buffalo’s page on it over here.