Lake Effect Snow Explained

You may have heard the term "Lake Effect Snow" while watching the national weather forecast. If you've never lived in a lake effect area, you've probably wondered what this weather phenomenon is.

Populations that live east or south of the Great Lakes are prone to this weather condition during the winter season. I live approximately forty miles east of Lake Ontario, at the foothills of the Tug Hill Plateau, so I'll explain the process as relates to my area. It is a good example of lake effect in other regions:

1. A very large mass of cold air sweeps through the region, usually arctic air from Canada.

2. The wind blows from a westerly, northwesterly direction, sweeping across the large, open body of the Great Lakes. The water temperature is normally warmer than the air.

3. This temperature differential produces clouds that move downwind, resulting in snow showers and snow squalls.

4. Areas of higher elevation inland usually receive larger amounts of snow than the low-lying or valley areas.

The elevation of my town, Camden, NY, is roughly 550 feet. Consequently, we can get hit pretty hard with heavy snow when the lake effect machine starts up. On average, our normal snow fall rate is between ten and twelve feet per winter. In the last eight years, we've had a few winters that exceeded twenty feet of snow. The accompanying photos are from Feb 2007. It was a battle to keep the driveway and walkways clear, as the snowfall exceeded twenty feet that winter.

An interesting aspect of this is how narrow the lake effect cloud bands can be. If you go north or south of my town, during a lake effect snow squall, the weather can be totally different. While we have almost zero visibility in whiteout conditions, it can be sunny and cloudless just ten miles above or below the band. These are also referred to as "streamers", and are very visible on Doppler radar.

It isn't unusual to see over 300 inches of snow just north and northwest of Camden! We've experienced lake effect snowfalls of three to six feet with a couple of days. It's great for snowmobilers but hell for driving and most people avoid going anywhere until the winds shift and the snowfall machine dies out. Area schools either delay opening or usually close if the snowfall is intense. These streamers can produce rates of 3-5" per hour at times.

"Winter sports" here consist of snowblowing, plowing, shoveling and roof-raking. Yes, we rake our roofs with extendible rods that have a beviled shovel head on the end. You put it up as far as you can and pull the snow down off the rood. It can be strenuous at times, but it helps to prevent roof leaks with melting snow that backs up behind ice dams on the roof's drip edge.

Fortunately, lake effect snow is very fluffy and light with much smaller water content than "normal" snow. It sounds crazy, but I would rather have the air temperature stay below twenty degrees during the winter if it's going to snow, due to the lighter weight of the snow.

Buffalo and other major cities get all the publicity when the lake effect machine cranks up, but please don't forget our small communities that go unmentioned!