1 December 2010
It’s December, which means that in Buffalo, temperatures are finally starting to settle in to their normal range (we’ve had a bit of a warm time so far this fall). And we have precipitation. The combination of those two usually means that the local weatherpeople, who haven’t had much to report on but rain so far, get to use their favorite phrase: “Lake effect snow”.
It’s snowing outside my office right now, rather vigorously, which is odd for the area north of the city; usually there’s a fairly distinctive snow line here, and only the “Southtowns” get any significant precipitation. With lake effect snow, it’s easy to see why: the tip of Lake Erie is usually the cutoff line, about 12 km south of the northern suburbs of Buffalo. Unless there’s something going on with the wind (it tends to blow directly from west to east here), we usually don’t see much of anything. (Belying that rumor that Buffalo gets a lot of snow – actually, in the past decade, Syracuse has had more snow than us. Heck, last year DC got more than we did. It’s amazing how one little blizzard in the 70’s will ruin your reputation for decades…) The current snow appears to be the remnants of a bigger system that’s passing through the northeast, but it will probably turn to ‘official’ lake effect snow by this afternoon.
Lake effect snow in the Buffalo area occurs when cold air moves across the relatively warm surface of Lake Erie, picks up moisture, and precipitates it in frozen form as it moves eastward over land and cools off. The “lake effect snow machine” only works until the lake freezes over, which shuts down the cycle. (In the case of the 1977 blizzard, the lake had already frozen, but enough snow had accumulated on its surface – partially due to the snow removal efforts of the City of Buffalo – that it blew right back on land and generally made life miserable for everyone.) A bit to the north and east of here and the main culprit becomes Lake Ontario, which is too deep to freeze completely in the winter, and which therefore produces lake effect snow for much longer in the winter than Lake Erie. Here’s a comparison of lake depths:
Lake Erie only reaches a piddling 210 feet (64 meters) deep, while Lake Ontario is nearly 4 times that (802 feet or 244 meters). That’s why Syracuse tends to get more lake effect snow than Buffalo; their “snow machine” almost never shuts down, because Lake Ontario rarely freezes over completely in the winter.
So don’t be afraid to come to Buffalo in the winter – it may be windy and cold, but the drifts hardly ever reach over your head, and you won’t have to drive a snowmobile to work. (I prefer sled dogs.)
NOTE: I didn’t realize that the NOAA .gif image up there would update itself, but now it’s showing a perfect example of that lake effect snow coming off of Lake Erie – right onto the Buffalo Southtowns, who are not appreciating the two feet of snow they’ve just gotten. (We only have about two inches up north, which shows you how localized those snow bands can be.)