Lake-effect Snow in the Great Lakes Region
- During late fall and winter, cold air flowing over the relatively warm waters of the Great Lakes leads to the production of lake-effect snow and thus enhanced snowfall totals immediately downwind of the lakes.
- Lake-effect snow production typically diminishes late in the winter season when the formation of lake ice leads to a reduction in the supply of relatively warm and moist air to the atmosphere.
- As global temperatures continue to rise and further warm the Great Lakes, areas in lake-effect zones will continue to see increasing lake-effect snowfall as a warmer atmosphere will be able to hold increasing amounts of moisture.
- Areas in southern lake-effect zones may see lake-effect snow replaced by lake-effect rain, as warming winter temperatures will result in an atmosphere that is less suitable for the formation of snow.
During the late fall and winter seasons in the Great Lakes region, the flow of cold air masses across the relatively warm waters of the Great Lakes waters results in the production of dramatic lake-effect snowfall downwind of the lakes, particularly on the southern and eastern shores. This lake-effect produces increased seasonal snowfall amounts compared with communities farther inland, as well as located upwind of the Great Lakes.
The Upper Peninsula Snowbelt
The Upper Peninsula of Michigan features one of the largest and most distinct snowbelts in the United States. Due to their large area and depth, the surface waters of Lake Superior, Lake Michigan, and Lake Huron freeze less completely. With open lake water throughout the winter months, lake-effect snow can fall continually across the Upper Peninsula and Canadian snowbelts. From the Porcupine Mountains and the Keweenaw Peninsula to Whitefish Point, snowfall is dramatically enhanced by lake effects. In some areas, annual snowfall totals commonly exceed 250 inches (635 cm) per year. The Keweenaw Peninsula, which averages more snowfall than any location in the United States east of the Mississippi River, owes much of its winter snowfall to lake effects. For comparison, Duluth, Minnesota, which lies outside the lake effect zone at the southwestern tip of Lake Superior, receives 78 inches (198 cm) per season.
Lake Michigan Snowbelt
Western Michigan, Northwestern Lower Michigan, and Northern Indiana can experience heavy lake-effect snow. As winds pass over Lake Michigan and generate snow, areas near Traverse City (MI), Muskegon (MI), Grand Rapids (MI), Kalamazoo (MI), South Bend (IN), and Elkhart (IN) can experience significant, often disruptive, lake-effect snowstorms. These snowfall events can reach far across Michigan and Indiana, but typically result in reduced snowfall totals before reaching areas such as Lansing (MI) and Fort Wayne (IN). When these cold winds flow across the short axis of a given lake (e.g., west to east across Lake Michigan), multiple effects of bands are predominant. In contrast, when these cold winds flow along the long axis of a given lake (e.g., north to south across Lake Michigan), a single band of lake-effect snow is often produced. Under cold northerly flow down the length of Lake Michigan, intense, but localized, lake-effect snowfall can be observed in Northwestern Indiana.
Lake Huron Snowbelt
Much of Southern Ontario to the east of Lake Huron can experience intense lake-effect snowfall and notorious whiteout conditions. The greatest accumulations typically occur on the Bruce Peninsula, which divides the main body of Lake Huron from the Georgian Bay to the east. Bounded by the lake on all sides except to the south, the Bruce Peninsula experiences lake-effect precipitation during most winter weather events, except when the wind is directly from the south or when Lake Huron is significantly frozen over.
Lake Ontario and Lake Erie Snowbelts
The region east and southeast of Lake Ontario frequently sees daily snowfall totals that are higher than anywhere in the United States. Syracuse, New York, receives significant lake-effect snow from Lake Ontario, averaging 116 inches (294 cm) of snow per year. Lake Erie produces a lake effect zone stretching from the eastern suburbs of Cleveland, Ohio to Buffalo, New York. Due to its relatively shallow depths, Lake Erie has the distinction of being the only Great Lake capable of completely freezing over. As it freezes throughout the winter, and the supply of moisture from the lake surface is cut off, lake-effect snow events cease.
Inland and Upwind Areas
Lake-effect snow is far less common in areas that are far enough inland or upwind from prevailing northwesterly winds over the lakes. Therefore, regions that see less lake-effect snow are typically those on the western and northern shores of the lakes, including Southeastern Michigan, Northwestern Ohio, Southeastern Wisconsin and Northeastern Illinois. However, lake-effect snow is possible when winds are out of the east or northeast. More frequently, the north side of a low-pressure system gathers more moisture as it travels westward over the lake, creating a phenomenon called lake-enhanced precipitation.
Climate Change and Snowfall
Overall, snowfall has increased in northern lake-effect zones in the Great Lakes basin even as snowfall totals in Illinois, Indiana, and Ohio have declined with rising temperatures. Warmer Great Lakes surface water temperatures and declining Great Lakes ice cover have likely driven the observed increases in lake-effect snow. As global temperatures continue to rise and further warm the Great Lakes, areas in lake-effect zones will continue to see increasing lake-effect snowfall. 1 Areas in more southern lake-effect zones may see lake-effect snow replaced by lake-effect rain, as winter temperatures will warm and be less suitable for snow.
- Burnett, A.W., Kirby M.E., Mullins, H.T., Patterson W.P. Increasing Great Lake-Effect Snowfall during the Twentieth Century: A regional Response to Global Warming? doi: 10.1175/1520-0442(2003)016<3535:IGLSDT>2.0.CO;2