Lake effect snow occurs when a cold air mass travels over a warmer body of water. The cold air is quickly warmed by the surface water, causing the air to become less dense and rise because of the temperature increase. The air, containing moisture because of its previous warm temperature over the lake, will condense, resulting in cloud formation. These clouds contain a great deal of moisture that falls when the clouds rise higher as they come into contact with land. Lake effect snowfall is highly dependent on the warm surface water from a lake, which means that a greater lake surface temperature will cause an increase in snowfall amounts and snow bands that affect a greater area. Research throughout the Great Lakes focusing on warmer water temperatures and annually greater snowfall amounts has shown this correlation between warmer water and greater magnitudes of snow. Ultimately, this concept leads to the idea that globally warmer temperatures result in an increase in lake effect snow because lakes are experiencing lower ice coverage and consistently warmer temperatures throughout the winter.
Every winter, areas such as Buffalo, NY face heavy snowfalls in short periods of time. These snowfalls are unlike the ones seen across the greater northeast and in other regions of the United States. These rapid snowstorms that develop over large lakes are a result of the atmospheric phenomenon known as lake effect snow. Lake effect snow is a very rare occurrence and only develops in a few places; some of these include along the shores of the Great Salt Lake, Lake Ontario, and Lake Baikal in Russia (Monmonier 2012). There are precise conditions for lake effect snow to occur, which is why it only occurs in specific parts of the world. In these areas, lake effect snow has a great influence on multiple aspects of society. On the one hand, these large snowfalls are a threat to life and property and can create major air and ground traffic problems (Burnett et al. 2013). On the other hand, recreational industries thrive with these storms, as do the potential for hydro power and the supply of water in these areas (Burnett et al. 2013).
Lake effect snow develops when cold air blows across a large, relatively warm body of water (Monmonier 2012). When air travels across the lake, it picks up the moisture from the warmer surface water. This new, warmer air expands, becomes less dense, and rises. Once the lake warms the air, the air follows the concepts of the ideal gas law, in which it continues to rise after it is warmed. Eventually, the moisture will condense and begin the development of clouds that carry large amounts of moisture. The clouds rise when they come into contact with land, causing the moisture to fall on the shorelines of the lake, a process known as orographic lifting. There are a number of factors that affect the amount of snowfall within a lake effect snowstorm; these factors include the difference in temperature between the lake and the air, wind direction, and the expanse of the lake that the air is moving across. All of these factors combine to create large magnitudes of snow in areas known as snow belts. In one case, Fulton, NY recorded an annual snowfall in 2004 of 147.7 inches, while in another instance, a meteorologist in Oswego, NY reported 17.5 inches of snow in two hours during January 26, 1972 (Monmonier 2012). One factor that affects the magnitude of these lake effect snow storms is the temperature of the lake. This is an important factor because as temperatures rise globally, there would also be rising lake temperatures, and more snow for areas affected by the lake effect concept. Therefore, the warmer the temperature of the lake, the greater magnitude of the lake effect snow storm, which also means global warming will result in an increase of lake effect snow events.
Many studies have observed the effect of the water temperature on the scale of lake effect snow storms. In one study from January of 2009, researchers analyzed the magnitude of lake effect snow in the great lakes region for all ice coverage, a water temperature of .05°C, and a water temperature of 3°C (Wright et al. 2013). The researchers used wind speeds, wind direction, and air temperature from January 2016, 2009 in order to create a model that would only test the effect of lake surface temperatures on the lake effect snow event (Wright et al. 2013). In doing so, Wright and his counterparts were able to control the other variables that could influence the magnitude of lake effect snow. Through the use of the Weather Research and Forecasting model (WRF), the study discovered that as the temperature of the lake increased, from being ice covered to being 3°C, the amount of precipitation, and the area to which it covers, increases (Wright et al. 2013). There is a noticeable increase in the amount of precipitation in the Great Lakes region, specifically from the ice covered data to the 0.05°C water temperature data. The 3°C diagram does not show a change in the structure of the precipitation, but instead shows there is an increase in the total accumulated snowfall (Wright at al. 2013). The researchers also discovered that the intensity of precipitation for the three levels of lake temperatures increased as the temperature did as well (Wright et al. 2013). This occurs because the warmer the lake, the more quickly the cold air mass is warmed and succumbs to the ideal gas law, meaning an increase in condensation and cloud formation. More specifically, the increase in water temperature creates instability due to the warm, moisture filled air close to the water surface and the colder air above it, which results in a greater escalation of upward moving water vapor, and allows for an increase in condensation (Wright et al. 2013). Therefore, in the Great Lakes Region, a change in the lake surface temperature results in a change in the magnitude of lake effect snow as demonstrated by Wright’s study and the concepts behind the ideal gas law.
Wright’s study from 2009 correlates directly with the idea that global warming could be a factor in an increasing amount of lake effect snowstorms. Global warming has the ability to reduce the ice coverage during the winter months in the Great Lakes. This reduction of ice would lead to an increase in the amount of lake effect snowfall based on the results of the experiment conducted by Wright and other researchers. A professor at York University, along with a team of international scientists, studied the warming of lakes all over the world. The study found that the Great Lakes faced a large increase in temperature between 1985 and 2009 (Aulakh 2015). In fact, Lake Superior was recorded as being the second fastest warming lake in the study (Aulakh 2015). This is significant because a rise in temperature of the Great Lakes affects the amount of ice able to form over the surface. In general, as lakes become increasingly free of ice, there is a greater amount of time for the temperature of the lake to warm (Aulakh 2015). This decline in ice allows for an increase in the lake effect snow events. One study in Lowville, NY, an area affected by lake effect snow, tracked the average snowfall amount per year in order to display the increase in snow totals over multiple years (Monmonier 2012). The study found that overall, there was an increase in snow totals from around 90 inches of snow in 1979 to almost 150 inches of snow in 2010. During the period of time in which these findings were concluded, global temperatures rose about .24°C, which ultimately leads to this warming in the lakes as previously stated (Aulakh 2015). Based on the findings in this study, it is possible that the overall increase in the temperature of the Great Lakes relates to the average snowfall increase seen in similar years. With a decline in ice coverage, and an increase in warmer lakes, more lake effect snowfall will occur because the lake will warm the air flowing over it for longer periods of time throughout the winter, especially in the coldest months.
Satellite derived surface temperatures of the Great Lakes, provided by the National Oceanic and Atmospheric Administration, displayed that there has been an upward trend in surface temperatures of the Great Lakes during the winter season beginning in the mid-nineties (Burnett et al. 2003). This trend suggests that the increases in snowfall are due to the thermal characteristics of the lakes rather than the winter air temperatures which did not show a similar trend. (Burnett et al. 2003). As previously discussed, these warmer water temperatures could be due to the global increase in temperatures. Furthermore, since the 1850s, ice records in the Great Lakes have shown that the ice season is starting increasingly later and ending earlier (Burnett et al. 2003). Both the increase in the stored heat of the Great Lakes and the decrease in ice coverage suggest that higher global temperatures have resulted in the greater amounts of lake effect snow due to the fact that the bodies of water remain ice free and have a greater warming effect on cold air moving across them.
Adam Burnett of Colgate University conducted a study on the effect global warming has on these lake effect snow events within the Great Lakes region. In the study, multiple researchers viewed snowfall at both non lake effect snow sites and lake effect snow sites to determine if snowfall changes in the lake effect locations are dependent on global warming (Burnett et al. 2003). Essentially, this study would determine if global warming is ultimately causing greater amounts of lake effect snow events because the non-lake effect areas should not see changes in snowfall like the lake effect areas would. Through analyzing 15 lake effect areas and 10 non lake effect areas, researchers found that since 1931, the lake effect locations had snowfall totals that demonstrated an increasing trend, compared to the non-lake effect areas which showed no significant trend (Burnett et al. 2003). If similar upward trends in snowfall were seen in non-lake effect regions, then it could be concluded that the trends were due to other disturbances in the atmosphere (Burnett et al. 2003). Researchers viewed lake temperatures provided by the NOAA to imply that the upward trend in lake water temperatures is responsible for the increase in snow totals in the lake effect zones (Burnett et al. 2003). These conclusions demonstrate the possibility that global warming is responsible for the increase in snowfall for areas in lake effect zones near the Great Lakes because it allows the lakes to reach higher temperatures than before.
There have been other confirmations of the noticeable increase in lake effect snow and even a decrease in snow in areas where lake effect events do not occur. Research conducted by GLISA discovered that in the Northern Great Lakes basin, snow totals in lake effect zones have increased, while in places such as Illinois, Ohio, and Indiana have seen a decrease in snow totals while temperatures have risen (Lake-Effect Snow in the Great Lakes Region). The researchers at Great Lakes Integrated Sciences concluded that the increase in global temperature is causing water temperatures to rise, and thus allowing for an increase in lake effect snow as there is also a decline in ice cover among the Great Lakes (Lake-Effect snow in the Great Lakes Region). The decrease in snow in areas that do not experience lake effect snow shows that rising temperatures are allowing for less snow, but areas near the Great Lakes only see more snow because warmer water temperatures resulting from global warming increase the magnitude of lake effect snow.
The conclusions surrounding these studies about warmer lake temperatures in relation to global warming and greater snowfall amounts brings up some potential future implications. The Intergovernmental Panel on Climate Change believes that by the end of the twenty first century, global surface temperatures could increase anywhere from 1.4° to 5.8°C (Burnett et al. 2003). If this prediction is true, this would mean a large increase in lake effect snow events due to the impact that global warming has on the factors affecting lake effect snow. It is important to realize that these snowfall events will continue to increase until there reaches a point in which the global temperatures are too warm that the number of below freezing days decreases greatly. Currently, it is possible to say that the lake effect snow events will continue to increase in magnitude due to the relationship between a globally warmer climate and lake temperatures. In the future, it will be important to keep track of globally rising temperatures and how these temperatures affect the water temperatures of the Great Lakes. Furthermore, an increase in lake effect snow could be beneficial for multiple industries, but also could be detrimental to human safety in the affected areas. Through continuing studies such as the ones previously done, it will be interesting to note if the increases in snow seen now remain, or if a new trend appears that may create a new theory as to why snowfall amounts are higher in the Great Lakes Region. As weather data becomes more and more available, it will be possible to use more consistent records to try and draw stronger conclusions about lake effect snow and what leads to an increase in its magnitude, such as warmer water.