With the holidays upon us and the nights getting shorter and colder, some wish summer’s warmth would return, while others like the cold and want to see some snow. For those who DO want to see snow, the old adage “be careful what you wish for” couldn’t be more apparent this time of year, as sometimes our thoughts do come to fruition. As early as October, but more prevalent, closer to Thanksgiving time, the Northeast and Great Lakes regions can often see snow, but not just your typical snow event, NO,NO,NO… I’m talking lake effect or lake enhanced snow! Lake effect snow occurs when cold air, often originating from Canada, moves across the open waters of the Great Lakes. This weather pattern for lake effect snowstorms typically happens between late November to mid-January and if you ask anyone who is a local from Buffalo, N.Y, or Cleveland, Ohio, they can tell you that the key component in determining which areas will receive lake effect snow, begin with the wind and what direction it comes from. You see, while heavy snow may be falling in one location, the sun may be shining just a mile or two away in either direction.
So what are the “ingredients” needed to turn cold, dry air into a major snowstorm? The first answer lies in the major contrast in temperature between the water and the air a few thousand feet above it. When a big contrast in temperature is created, the more snow an area sees. A difference of 25 degrees or more is enough to bring about an environment that can fuel very heavy snows. As the cold air passes over the yet unfrozen and relatively warm waters of the Great Lakes, warmth and moisture from the water lift a few thousand feet into the sky, and when air rises, clouds form and grow into narrow bands that can produce 2 to 3 inches of snow per hour! Once again, this often happens in late fall, when lake water is still warm from summer and cold air starts sweeping down from Canada. The second piece of the puzzle is the wind and how far the wind has to travel over a body of water. The further cold air travels over one of the lakes surface, the more moisture that is available for lake-effect snow. In addition to wind direction, the topography of the land is also important. Once the snow reaches land, elevation contributes to lifting the moisture higher in the atmosphere, enhancing snowfall rates and is termed “orographic effect.” One such place that is common to seeing this “orographic effect”, is The Tug Hill plateau. Located between Lake Ontario and the Adirondack Mountains in western New York, it is here that an annual snowfall approaches and sometimes exceeds 200 inches! Residents from Northern Wisconsin to Upstate New York are keenly aware of the phenomenon, because some residents received upwards of 6 feet of snowfall during an epic lake-effect event, in these areas. Unfortunately, when that happens, the weight of the snow can collapse roofs and potentially led to people losing their lives.
So while much of the U.S. doesn’t have the possibility of seeing lake-effect snow, the few that do, have the chance of shattering past snowfall amounts when it comes to this unique set-up from Mother Nature. That’s all for today, so have a great rest of your week, God bless, stay warm, and we’ll see you next week.