Lake-effect Snow - Great Lakes Region, U.S. Northeast

Great Lakes Region, U.S. Northeast

Cold winds in the winter typically prevail from the northwest in the Great Lakes region, producing the most dramatic lake-effect snowfalls on the southern and eastern shores of the Great Lakes. This lake-effect produces a significant difference between the snowfall on the southern/eastern shores and the northern and western shores of the Great Lakes.

Lake-effect snows on the Tug Hill Plateau (east of Lake Ontario) can frequently set daily records for snowfall in the United States. Syracuse, New York, is directly south of the Tug Hill Plateau and receives significant lake-effect snow from Lake Ontario, averaging 115.6 inches (294 cm) of snow per year, which is enough snowfall to often be considered one of the "snowiest" large cities in America. The communities of Redfield in Oswego County and Montague and North Osceola in Lewis County, all on the Tug Hill Plateau, average over 300 inches (762 cm) of snow each winter. In February, 2007, a prolonged lake-effect snow event left 141 inches (358 cm) of snow on the Tug Hill Plateau.

A small amount of lake-effect snow from the Finger Lakes falls in upstate New York as well. The Appalachian Mountains and Atlantic Ocean largely shield New York City and Philadelphia from picking up any lake-effect snow; snow there tends to come from mesocyclonic storm systems mixing with cold temperatures.

Lake Erie produces a similar effect for a zone stretching from the eastern suburbs of Cleveland through Erie to Buffalo. Remnants of lake-effect snows from Lake Erie have been observed to reach as far as Garrett County, Maryland. Lake Erie has the distinction of being the only Great Lake capable of completely freezing over during the winter, because of its relative shallowness. Once frozen, the resulting ice cover alleviates lake-effect snow downwind of the lake.

A very large snowbelt in the United States is the one in the Upper Peninsula of Michigan, near the cities of Houghton, Marquette, and Munising. These areas average 250–300 inches (635–762 cm) of snow each season. For comparison, on the western shore, Duluth, Minnesota receives 78 inches (198 cm) per season. Lake Superior and Lake Huron rarely freeze because of their size and depth; hence, lake-effect snow can fall continually in the Upper Peninsula and Canadian snowbelts during the winter months. Main areas of the Upper Peninsula snow belt include the Keweenaw Peninsula and Baraga, Marquette and Alger counties, where Lake Superior contributes to lake-effect snow, making them a prominent part of the midwestern snow belt. Records of 390 inches (991 cm) of snow or more have been set in many communities in this area. The Keweenaw Peninsula averages more snowfall than almost anywhere in the United States—more than anywhere east of the Mississippi River and the most of all non-mountainous regions of the continental United States. Because of the howling storms across Lake Superior, which cause dramatic amounts of precipitation, it has been said that the lake-effect snow makes the Keweenaw Peninsula the snowiest place east of the Rockies. Only one official weather station exists in this region. Located in Hancock, Michigan, this station averages well over 210 inches (533 cm) per year. Farther north in the peninsula, lake-effect snow can occur with any wind direction. The road commission in Keweenaw County, Michigan collects unofficial data in a community called Deleware, and it strictly follows the guidelines set forth by the National Weather Service. This station averages over 240 inches (610 cm) per season. Even farther north, a ski resort called Mount Bohemia receives an unofficial annual average of 273 inches (693 cm). Herman, Michigan, averages 236 inches (599 cm) of snow every year. Lake-effect snow can cause blinding whiteouts in just minutes, and some storms can last days.

Western Michigan, western Northern Lower Michigan, and Northern Indiana can get heavy lake-effect snows as winds pass over Lake Michigan and deposit snows over Muskegon, Traverse City, Grand Rapids, Kalamazoo, New Carlisle, South Bend, and Elkhart, but these snows abate significantly before Lansing or Fort Wayne, Indiana. When winds become northerly, or aligned between 330 and 390 degrees, a single band of lake-effect snow may form, which extends down the length of Lake Michigan. This long fetch often produces a very intense, yet localized, area of heavy snowfall, affecting cities such as Laporte and Gary Indiana.

Lake-effect snow is uncommon in Detroit, Milwaukee, and Chicago, because the region's dominant winds are from the northwest, making them upwind from their respective Great Lakes. However, they too can see lake-effect snow during easterly or north-easterly winds. More frequently, the north side of a low-pressure system picks up more moisture over the lake as it travels west, creating a phenomenon called lake-enhanced precipitation.