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”.
Lake-Effect snow has a range of different intensities depending upon certain factors. The difference between the air temperature and the water temperature will determine how much moisture is taken into the air. Warmer water and colder air makes for more snow. Also the distance the air has to travel across the lake will determine how much moisture the air is able to obtain. The ability of the storm to travel inland will be determined by the intensity of the storm’s winds. Storms also are able travel farther inland in late fall and early winter.
Lake-Effect snow storms typically take the form of flurries and are limited to a small areas. Often times these flurries may stay in an area for a long period of time and then suddenly move to another area with the shift of surface winds. These “bands” of clouds that produce the snow can become as large as fifty miles wide and a hundred miles long (www.islandnet.com). These bands of clouds are able to remain in one defined region for up to 48 hours, and often times are producing snow at a rate of two to six inches of snow per hour. Remarkably one area may receive over 48 inches of snow and an area miles away may only receive eight inches.
Many believe that the greatest factor to increasing lake-effect snowfall is due to global warming. Temperatures in the twentieth century have been rising at a rate of about .6 degrees Celsius per year. In the northern hemisphere scientists have noticed that lakes are typically melting all their ice two weeks earlier than normal. Also since 1850 lakes have been freezing about six days later. Many have come to the conclusion that this is due to human’s emission of greenhouse gases. These greenhouse gases have caused an increasing hole in our protective ozone layer around the earth. This allows for temperatures to increase. These increasing temperatures increase the temperature of the great lakes. These are huge bodies of water and are able to retain their heat long into the winter. When cold arctic winds are pushed south into the great lakes region and sweep across the lakes. The dramatic temperature difference between the lake water and the air cause masses of moisture to be taken up. (Burnett, et.al., 2003)
These lake-effect blizzards also have a huge economic impact on areas. They are able to generate money for some areas and also cost them at the same time. The 2007 blizzards cost millions of dollars in damages. These areas are also very popular for recreational sports such as cross country skiing, snowshoeing, and snowmobiling. Many people that enjoy these sports are drawn to these areas because of their record snowfall. These areas are also economically benefited by the snowfall through hydroelectricity. The massive runoff created by the snow helps to power many households and employ workers. The large snow averages also have created many businesses that specialize in snow removal.
These economic gains that are effect of the lake-effect blizzards are still not enough to compensate for the damage the cause. Agricultural businesses are devastated by these large snows. Many businesses are unable to operate because they do not receive there necessary supplies. Also any and all commercial freighting by road is completely shut down by these blizzards.
Lake-effect blizzards are yet another awe inspiring power of Mother Nature that demand respect. Humans only choice is to be well prepared for these storms and know how to handle massive amounts of snow in short time periods.