Buffalo's incredible snowstorm
The area in and around Buffalo, NY, received anywhere from ten to 80 inches of snow.
FARGO — Between November 16 and November 20, the area in and around Buffalo, NY, received anywhere from ten to 80 inches of snow. While the event may have produced more snow than normal, the mechanism which caused it is very typical in the Great Lakes Region.
Lake Effect Snow (LES) occurs when cold air travels over the much warmer lake waters. This produces an unstable atmosphere which causes convective bands of snow to develop. Greater temperature differences produce greater instability, and heavier snowfall rates. Strong winds push these bands inland in a process which can last up to a few days.
Each of the five Great Lakes has its own unique features when it comes to LES. Lake Erie is the shallowest of the Great Lakes, and typically in winter it freezes over. This means that Lake Erie has a much shorter LES season than other Great Lakes. Nonetheless, Lake Erie can produce some powerful LES events, as was seen over the weekend..
Lake Erie is oriented mainly southwest-to-northeast. It is 241 miles long and 57 miles wide. Normally, the wind direction behind a cold front over Lake Erie is northwesterly. Colder air arriving from the north has only 57 miles of lake water to work with. This will typically cause a series of "finger-like" bands which produce moderate snowfall rates from the eastern suburbs of Cleveland all the way up into the southern Buffalo metro.
However, every so often a cold wind will come from the west-southwest, and this can produce big snowfall events. Since this colder air has 241 miles of warm lake waters to work with, this type of setup usually produces a single band of intense LES. The recent LES band was nearly 200 miles long and 30 miles wide. It produced snowfall rates of up to 2 to 3 inches per hour, with thunder and lightning at times. This single band meandered a bit over the course of its life, drifting south at times and then north. What was unique about this particular band was that it drifted further north than usual, and in doing so it brought its heaviest snowfall rates into downtown Buffalo.
These meandering LES bands can deliver a wallop to whatever locations they happen to drift over. On 21 November 2014, a very similar LES band set up across the south Buffalo metro. It produced up to 7 feet of snow in the south suburbs, with Cowlesville the winner with 88 inches. That snow mainly missed Buffalo, with the Buffalo Airport reporting just 16.9 inches of snowfall.
This time around, the snow band meandered for a bit over the Buffalo Airport, and 36.6 inches of snow was reported. For this event, the highest unofficial report is 81.2 inches in Hamburg.
Not every LES event brings this much snow, and in some years such snowfall totals do not even happen. The average winter snowfall for Buffalo, NY (at the airport) is 95 inches, most of which falls as LES.
Due to the prevailing northwest wind direction in winter, the most common recipients of LES events are: Buffalo, Syracuse, Rochester and Watertown, NY; Erie, PA; Cleveland, OH; Grand Rapids, Traverse City, and Marquette, MI; and parts of southwestern Ontario. If you look at a map, you will notice that these locations are generally on the eastern or southern edge of whatever lake they border.
LES is not common in Chicago because it would require a steady northeast wind, which is uncommon, although a steady north wind can bring intense snowfall to the east-Chicago areas of Gary and Hammond, IN.
Finally, LES is very localized. Unlike the snowstorms in the Midwest and Plains which can produce a lot of snowfall over a large area, LES is generally confined to relatively small areas near the lakes. It all comes down to location relative to the wind direction and the temperature difference between the lake water and the incoming colder air.