Early this February the states surrounding the great lakes in the northeast were pounded by lake-effect snow storms. Some areas saw more than four feet of snow. These states are accustomed to lake-effect snow storms, but it has been some time since they last saw one of this magnitude. Some areas saw up to 140 inches in less than twelve days. The storm was accountable for 35 deaths. (msn.com 2007)
States on the lee, or down wind, sides of the great lakes receive lake-effect snow every year. For some cities this can push the average snowfall up to 400 inches. During the February storm of this year records were broken for the most snowfall in one storm. For a duration of the storm snow was falling at a rate of six inches or more per hour. Some of the images captured from the event leave some in disbelief that such a thing could even happen. Storms of this magnitude completely shut down all activity. Many areas do not have equipment capable of handling such mass amounts of snow, and even if they do the task is overwhelming. (weather.com 2006)
The concept of lake-effect snow is rather simple. It starts when cold arctic air from Canada moves southwest across the great lakes, which are warmer than the air. As the air moves across the lakes evaporation occurs. The moist air is cooled as it is lifted up and then turned into snow. This snow does not stop until the cold arctic winds stop drifting across the lakes. Hills and valleys on the shore of the lakes intensify the amount of snow an area receives. The shore of the lakes as well as, any hills or valleys, cause the masses of moist air to slow down and “pile up”.