The phenomenon known as lake effect snow is seen most commonly on the Great Lakes during fall and winter in the northern U.S. However, lake effect snow does occur in freak situations on other lakes and even ponds in the U.S. This phenomenon happens when specific weather conditions collide together to produce lake effect snow.
Is Lake effect Snow Real Snow?
The main thing to note about lake effect snow is that the lake water has to be warm, and freezing air has to blow over the water. Lake effect snow is not a snowfall that blankets an entire region, but it has the potential to reach a 10-mile band. Lake effect snow falls over the lake and the land downwind from the icy blast of wind.
Yes, lake effect snow is real snow. Lake effect snow falls from an actual cloud formed by the specific weather conditions that create it.
CNN’s Brandon Miller recently reported “The Great Lakes is the only place where lake effect snow occurs in the United States, except occasionally at the Great Salt Lake in Utah”, on 11-17-2022, and this is untrue.
Lake effect snow can occur anywhere the conditions are right over a lake or pond. Right before Christmas, 2022, Lakehub publisher Simon Trask, in Texas, reported, “I personally witnessed pond-effect snow when we got that cold blast before Christmas. There were 20 mph winds and a 20 degree temperature drop in an hour while I was out hunting, and snow was coming up off a 5 acre pond!”
What Is the Difference Between Lake Effect Snow and Regular Snow?
Lake effect snow develops exactly like snow. Microscopic ice crystals in clouds cling together in clouds and turn into snowflakes. When enough crystals adhere to each other, they become too heavy for the cloud to hold them, and they fall to the ground. If the air is a bit warmer than 32 degrees, the ice crystals melt around the edges, which produce large snowflakes.
The difference is that wind direction is a key component. Lake effect snow occurs when cold air moves over a water body warm enough that heat and moisture rise up to form a cloud over the water. The cloud grows, and tiny ice crystals form in the cloud. If the ice crystals grow large enough to become heavy enough to fall, lake effect snow results.
It can be a pleasant sunny winter day all around a lake’s region, and typically, the lake effect snow will fall pretty close to the lake’s shores. During a broader storm system like what happens over the Great Lakes, that storm can produce a five to ten-mile-wide band of lake effect snow.
How Do Meteorologists Explain Lake Effect Snow?
The meteorology industry’s scientific explanations for the phenomenon of lake effect snow production are a little more complicated than the above information. The weather conditions that produce lake effect snow comprise chance variation factors.
Wind direction, water temperatures, air temperatures, air-to-water temperature difference, and the physical geography of the land and water are the foundational elements in explaining how a weather system produces lake effect snow. Forecasting lake effect snow is highly challenging for meteorologists.
First, we have to understand what “wind mb” means. Meteorologists use a metric unit for pressure called a millibar; mb is a millibar. 1000 millibar = 1 bar = regular atmosphere. The average pressure at sea level is 1013.25 millibars. For example, consider a “unit area” of 1 square inch. At sea level, the weight of the air above this unit area would (on average) weigh 14.7 pounds. This means pressure applied by this air on the unit area would be 14.7 pounds per square inch.
The U.S. National Weather Service conducted a four-year study on lake effect snow. It found three factors particularly critical: 1. 850 mb temperature, 2. 850-700 mb mean relative humidity, and 3. 1000-850 mb wind speed in order to produce lake effect snow.
In the simplest terms possible, this translates into the following weather conditions on how lake effect snow forms on the Great Lakes. You will understand how the following scientific explanation of the Great Lakes lake effect snow formation transfers over to the Great Salt Lake region in Utah more clearly in the Utah section of this article.
From Meteorologist Jeff Haby:
1. The presence of a cold air mass flowing over a lake is required. A polar air mass needs to be deep (at or above the 700 millibar level) with small directional shear (a change in wind direction less than 60° from surface to 700 millibars) for significant lake effect snow to occur. Polar air masses have low dew points, cold temperatures, and a high degree of stability.
2. Polar air masses originate from the continental polar regions of Canada. They filter over lakes after a low-pressure system passes to the east. Cold air rushes in from the north and northwest with counterclockwise winds. If the air mass is at least 55.4 °F colder than the lake, heavy lake effect snow can occur. Once the air above the lake water is colder than the water temperature, another important and smaller air mass develops just above the lake surface.
3. The lake influences the air above its surface. When the air is colder, the warmer water conducts and convects heat upward in accordance with the second law of thermodynamics. Because of conduction, the air just above the lake is about the same temperature as the lake, but decreases rapidly above this very thin layer. Above this layer, mixing of cold and warm air occurs. This mixing decreases with height. The result is a temperature profile, which decreases almost linearly. After the heat moves sufficiently vertical above the lake, the warm water has no effect. The air above this point will either remain at a constant temperature or could rise since the more dense cold air descends.
4. After the cold air has moved over a significant fetch [area] of warm lake water, this temperature profile depends on the temperature of the air and temperature of the lake water, the wind speed, and the thickness of the cold air mass. Higher winds steepen the temperature gradient since the modified air has less time to convect.
5. The air near the lake surface and colder air aloft [above] cause the atmosphere to be conditionally or absolutely unstable. The air becomes saturated at the surface since the lake is evaporating water. Because the colder air above the surface of the lake sustains a lower saturation vapor pressure than the warmer air at the surface, saturation and condensation into droplets occurs, which is called steam fog [the lake effect snow cloud] Convection results and leads to the development of snow crystals.
6. Once this air mass has traveled over the open water and blows over land, the process of friction intensifies convection. While the air is flowing over the water, it moves at a greater wind speed than over the land due to decreased frictional drag. This causes the air to pile up along the shore. Once piled up, the air has nowhere to go but up. Over land, the orographic effect* increases the air uplift. Higher elevations increase cooling and condensation of water vapor in the air. Hilly areas exist on the eastern side of many of the Great Lakes, increasing lake effect snow there.
* The orographic effect occurs when air masses are forced to flow over high topography [mountains].
Jeff Haby
Is Lake Effect Snow Heavy or Fluffy?
Lake effect snow’s composition depends somewhat on the temperature of the water versus the temperature of the winds cooling the air over the water. The storm’s origin that creates lake effect snow also plays a role in the snowflake’s composition.
Lake effect snow is typically fluffier and drier than a snowfall produced over an entire region. A snowflake’s fluffy or heavy composition depends on a snow-to-water ratio, along with the air versus the water temperature. Lake effect snow has a higher snow-to-water ration than other snow, which results in drier, lighter, and fluffier snowflakes.
Simply put, if for every 10 inches of snow, there would be 1 inch of water (10:1). For example, when Chicago experiences a major snow event, its snow-to-water ratio on average is 6-10:1. Lake Michigan’s lake effect snow in Chicago produces a snow-to-water ratio of 20-50:1. In contrast, the Canadian Atlantic Clipper storms (quick bursts of snow with 35-45 mph winds), produce lake effect snow with a snow-to-water ratio of 20:1.
What Cities Get Lake Effect Snow?
Lake effect snow conditions occur in fall and winter when lake water is at its warmest temperature after the summer. As the winter continues, the water cools down, so lake effect snow conditions are not as frequent in late winter. The cities close to the Great Lakes experience the most lake effect snow in the U.S.
Syracuse, Rochester, and Buffalo, New York, Erie, Pennsylvania, Cleveland, Ohio, Grand Rapids, Michigan, and Duluth, Minnesota, get the most lake effect snow. Detroit, Toledo, Milwaukee, and Chicago receive much less lake effect snow because they are on the west side of Lakes Michigan and Erie, and the prevailing winds are from the west.
Tug Hill Plateau, south of Watertown, N.Y., on the eastern end of Lake Ontario receives the heaviest lake effect snowfall in the U.S. This region is one of the snowiest places in the U.S. The other region that receives lake effect snow is the Great Salt Lake region in Utah. The Wasatch Mountains line Great Salt Lake on its east and north, and the Oquirrh Mountains lie to its west.
What Area Gets the Most Lake Effect Snow?
The Great Lakes regions receive the most lake effect snow in the U.S., and the Great Salt Lake region in Utah receives the lake effect snow that Utah claims as the “Greatest Snow on Earth”.
Can Lake Effect Snow Happen Anywhere?
While lake effect snow is most common in the Great Lakes region in the U.S., lake effect snow can occur anywhere the weather conditions come together to produce lake effect snow. Lake effect snow is not common in other areas of the U.S. Lake effect snow does and can occur when the specific conditions of cold air over warm water are at the right temperatures with the right wind velocity anywhere in the world.
Does Utah Get Lake Effect Snow?
The Great Salt Lake and its surrounding mountains, the Wasatch and Oquirrh Mountain ranges, have unique geography that creates the conditions that produce lake effect snow. The ski resorts in the Wasatch Mountains benefit from Salt Lake’s lake effect snow with its legendary light snow that has enough body to support skis and snowboards on an upper layer of snow without scraping the base underneath.
Lake effect snowfall contributes about 6% of the annual snowfall surrounding Salt Lake, according toJim Steenburgh, University of Utah professor of atmospheric sciences and the author of Secrets of the Greatest Snow on Earth (what Utah markets its snow as). This amount of lake effect snow is attributed to normal Salt Lake water levels.
The most affected areas of Salt Lake’s lake effect snow storms occur on the southern and eastern areas of the lake. Winds flying across the Great Basin smash into the Wasatch Mountain range and then brusquely changes positions from around 4,300 feet to 11,000-foot mountain peaks.
Other meteorological professionals report that in an average year, Salt Lake’s lake effect snowfall contributes 5 to 10% of the snow that falls in the Big Cottonwood Canyon, southeast of Salt Lake in the Wasatch Range. The extremely popular Solitude Mountain Resort, Brighton, Snowbird, and Alta Ski Area ski resorts call Cottonwood Canyon home.
