Lake effect snow
Overview
 
Lake-effect snow is produced during cooler atmospheric conditions when cold winds move across long expanses of warmer lake
Lake
A lake is a body of relatively still fresh or salt water of considerable size, localized in a basin, that is surrounded by land. Lakes are inland and not part of the ocean and therefore are distinct from lagoons, and are larger and deeper than ponds. Lakes can be contrasted with rivers or streams,...

 water, providing energy and picking up water vapor
Water vapor
Water vapor or water vapour , also aqueous vapor, is the gas phase of water. It is one state of water within the hydrosphere. Water vapor can be produced from the evaporation or boiling of liquid water or from the sublimation of ice. Under typical atmospheric conditions, water vapor is continuously...

 which freezes and is deposited on the leeward shores. The same effect over bodies of salt water is called ocean effect snow, sea effect snow, bay effect snow, or even sound effect snow in the most blisteringly extreme cases.
Encyclopedia
Lake-effect snow is produced during cooler atmospheric conditions when cold winds move across long expanses of warmer lake
Lake
A lake is a body of relatively still fresh or salt water of considerable size, localized in a basin, that is surrounded by land. Lakes are inland and not part of the ocean and therefore are distinct from lagoons, and are larger and deeper than ponds. Lakes can be contrasted with rivers or streams,...

 water, providing energy and picking up water vapor
Water vapor
Water vapor or water vapour , also aqueous vapor, is the gas phase of water. It is one state of water within the hydrosphere. Water vapor can be produced from the evaporation or boiling of liquid water or from the sublimation of ice. Under typical atmospheric conditions, water vapor is continuously...

 which freezes and is deposited on the leeward shores. The same effect over bodies of salt water is called ocean effect snow, sea effect snow, bay effect snow, or even sound effect snow in the most blisteringly extreme cases. The effect is enhanced when the moving air mass is uplifted by the orographic
Orographic lift
Orographic lift occurs when an air mass is forced from a low elevation to a higher elevation as it moves over rising terrain. As the air mass gains altitude it quickly cools down adiabatically, which can raise the relative humidity to 100% and create clouds and, under the right conditions,...

 influence of higher elevations on the downwind shores. This uplifting can produce narrow but very intense bands of precipitation, which deposit at a rate of many inches of snow each hour, often resulting in copious snowfall totals. The areas affected by lake-effect snow are called snowbelt
Snowbelt
Snowbelt is a term describing of a number of regions near the Great Lakes in North America where heavy snowfall in the form of lake-effect snow is particularly common. Snowbelts are typically found downwind of the lakes, principally off the eastern and southern shores...

s. This effect occurs in many locations throughout the world but is best known in the populated areas of the Great Lakes
Great Lakes
The Great Lakes are a collection of freshwater lakes located in northeastern North America, on the Canada – United States border. Consisting of Lakes Superior, Michigan, Huron, Erie, and Ontario, they form the largest group of freshwater lakes on Earth by total surface, coming in second by volume...

 of North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

, and especially Western New York
Western New York
Western New York is the westernmost region of the state of New York. It includes the cities of Buffalo, Rochester, Niagara Falls, the surrounding suburbs, as well as the outlying rural areas of the Great Lakes lowlands, the Genesee Valley, and the Southern Tier. Some historians, scholars and others...

, northwestern Pennsylvania, northeastern Ohio, southwestern and central Ontario, northwestern and northcentral Indiana
Indiana
Indiana is a US state, admitted to the United States as the 19th on December 11, 1816. It is located in the Midwestern United States and Great Lakes Region. With 6,483,802 residents, the state is ranked 15th in population and 16th in population density. Indiana is ranked 38th in land area and is...

 (mostly between Gary, IN and Elkhart, IN), and western Michigan
Michigan
Michigan is a U.S. state located in the Great Lakes Region of the United States of America. The name Michigan is the French form of the Ojibwa word mishigamaa, meaning "large water" or "large lake"....

. The Tug Hill Plateau
Tug Hill Plateau
The Tug Hill Plateau is an upland region in upstate New York in the USA, famous for heavy winter snow. The Tug Hill Region is west of the Adirondack Mountains and is separated from the Adirondacks by the Black River Valley. Although the region is and has traditionally been known as the Tug Hill...

 of New York State has the most snow amounts of any non-mountainous location within the continental U.S., followed by the Upper Peninsula of Michigan
Upper Peninsula of Michigan
The Upper Peninsula of Michigan is the northern of the two major land masses that make up the U.S. state of Michigan. It is commonly referred to as the Upper Peninsula, the U.P., or Upper Michigan. It is also known as the land "above the Bridge" linking the two peninsulas. The peninsula is bounded...

, which can average over 200 inches (5.1 m) of snow per year.

If the air temperature is not low enough to keep the precipitation frozen, it falls as lake-effect rain
Rain
Rain is liquid precipitation, as opposed to non-liquid kinds of precipitation such as snow, hail and sleet. Rain requires the presence of a thick layer of the atmosphere to have temperatures above the melting point of water near and above the Earth's surface...

. For lake-effect rain or snow to form, the air moving across the lake must be significantly cooler than the surface air (which is likely to be near the temperature of the water surface). Specifically, the air temperature at an altitude where the air pressure is 850 millibars (roughly 1.5 vertical kilometres) should be 13 °C lower than the temperature of the air at the surface. Lake-effect occurring when the air at 850 millibars is much colder than the water surface can produce thundersnow
Thundersnow
Thundersnow, also known as a winter thunderstorm or a thunder snowstorm, is a relatively rare kind of thunderstorm with snow falling as the primary precipitation instead of rain. It typically falls in regions of strong upward motion within the cold sector of an extratropical cyclone...

, snow showers accompanied by lightning
Lightning
Lightning is an atmospheric electrostatic discharge accompanied by thunder, which typically occurs during thunderstorms, and sometimes during volcanic eruptions or dust storms...

 and thunder
Thunder
Thunder is the sound made by lightning. Depending on the nature of the lightning and distance of the listener, thunder can range from a sharp, loud crack to a long, low rumble . The sudden increase in pressure and temperature from lightning produces rapid expansion of the air surrounding and within...

 (caused by larger amounts of energy available from the increased instability).

Lake Effect season begins in mid-August, as cooler air from Canada starts to get more vigorous. The air is modified and warmed, which the precipitation type would be rain instead of snow. Also from mid-August to about mid-October, waterspouts become more common on Lake Erie
Lake Erie
Lake Erie is the fourth largest lake of the five Great Lakes in North America, and the tenth largest globally. It is the southernmost, shallowest, and smallest by volume of the Great Lakes and therefore also has the shortest average water residence time. It is bounded on the north by the...

 due to the cooler air. Waterspouts and rains are the harbingers of Lake Effect season beginning.

Formation

There are several key elements that are required to form lake-effect precipitation and which determine its characteristics: instability, fetch, wind shear, upstream moisture, upwind lakes, synoptic (large)-scale forcing, orography/topography, and snow or ice cover.

Instability

A temperature difference of 13°C between the lake temperature and the height in the atmosphere (~1,500 meters or ~4,921 feet) at which barometric pressure dials back to 850 millibars provides for absolute instability and allows vigorous heat and moisture transportation vertically. Atmospheric lapse rate and convective depth are directly affected by both the mesoscale lake environment and the synoptic environment; a deeper convective depth with increasingly steep lapse rates and a suitable moisture level will allow for thicker, taller lake effect precipitation clouds and naturally a much greater precipitation rate.

Fetch

The distance that an airmass travels over a body of water is called fetch. Because most lakes are irregular in shape, different angular degrees of travel will yield different distances; typically a fetch of at least 100 km is required to produce lake effect precipitation. Generally, the larger the fetch the more precipitation that will be produced. Larger fetches provide the boundary layer with more time to become saturated with water vapor and for heat energy to move from the water to the air. As the air mass reaches the other side of the lake, the engine of rising and cooling water vapor pans itself out in the form of condensation and falls as snow, usually within 40 kilometers of the lake.

Wind shear

Directional shear is one of the most important factors governing the development of squalls; environments with weak directional shear typically produce more intense squalls than those with higher shear levels. If directional shear between the surface and the height in the atmosphere at which the barometric pressure has scaled back to a reading of 700 mb is greater than 60 degrees, nothing more than flurries can be expected. If the directional shear between the body of water and the vertical height at which the pressure reads 700 mb is between 30 and 60 degrees, weak lake-effect bands are possible. In environments where the shear is less than 30 degrees, strong, well organized bands can be expected.

Speed shear is less critical, but should be relatively uniform. The wind speed difference between the surface and vertical height at which the pressure reads 700 mb should be no greater than 40 knots (78.4 km/h) so as to prevent the upper portions of the band from shearing off. However, assuming the surface to 700mb winds are uniform, a faster overall velocity will work to transport moisture quicker from the water, and the band will travel much further inland.

Upstream moisture

A lower upstream relative humidity will make it more difficult and time consuming for lake effect condensation, clouds and precipitation to form. The opposite is true if the upstream moisture has a high relative humidity, allowing lake effect condensation, cloud and precipitation to form more readily and in a greater quantity.

Upwind lakes

Any large body of water upwind will impact lake-effect precipitation to the lee of a downwind lake by adding moisture or pre-existing lake-effect bands, which can re-intensify over the downwind lake. Upwind lakes do not always lead to an increase of precipitation downwind.

Synoptic forcing

Vorticity advection aloft and large upscale ascent help increase mixing and the convective depth, while cold air advection lowers the temperature and increases instability.

Orography and topography

Typically lake-effect precipitation will increase with elevation to the lee of the lake as topographic forcing squeezes out precipitation and dries out the squall much faster.

Snow and ice cover

As a lake gradually freezes over, its ability to produce lake-effect precipitation decreases for two reasons. Firstly, the open ice-free liquid surface area of the lake shrinks. This reduces fetch distances. Secondly, the water temperature nears freezing, reducing overall latent heat energy available to produce squalls. To end the production of lake-effect precipitation, a complete freeze is often not necessary.

Even when precipitation is not produced, cold air passing over warmer water may produce cloud cover. Fast moving mid-latitude cyclones, known as Alberta clipper
Alberta clipper
An Alberta clipper is a fast moving low pressure area which generally affects the central provinces of Canada and parts of the Upper Midwest and Great Lakes regions of the United States. Most clippers occur between December and February, but can also occur occasionally in the month of November...

s, often cross the Great Lakes. After the passage of a cold front, winds tend to switch to the northwest, and a frequent pattern is for a long-lasting low-pressure area to form over the Canadian Maritimes, which may pull cold northwestern air across the Great Lakes for a week or more, commonly identified with the negative phase of the North Atlantic Oscillation (NAO). Since the prevailing winter winds tend to be colder than the water for much of the winter, the southeastern shores of the lakes are almost constantly overcast, leading to the use of the term The Great Gray Funk as a synonym for winter. These areas allegedly contain populations that suffer from high rates of seasonal affective disorder
Seasonal affective disorder
Seasonal affective disorder , also known as winter depression, winter blues, summer depression, summer blues, or seasonal depression, is a mood disorder in which people who have normal mental health throughout most of the year experience depressive symptoms in the winter or summer, spring or autumn...

, a type of psychological depression thought to be caused by lack of light.

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
Tug Hill Plateau
The Tug Hill Plateau is an upland region in upstate New York in the USA, famous for heavy winter snow. The Tug Hill Region is west of the Adirondack Mountains and is separated from the Adirondacks by the Black River Valley. Although the region is and has traditionally been known as the Tug Hill...

 (east of Lake Ontario
Lake Ontario
Lake Ontario is one of the five Great Lakes of North America. It is bounded on the north and southwest by the Canadian province of Ontario, and on the south by the American state of New York. Ontario, Canada's most populous province, was named for the lake. In the Wyandot language, ontarío means...

) can frequently set daily records for snowfall in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

. Syracuse, New York
Syracuse, New York
Syracuse is a city in and the county seat of Onondaga County, New York, United States, the largest U.S. city with the name "Syracuse", and the fifth most populous city in the state. At the 2010 census, the city population was 145,170, and its metropolitan area had a population of 742,603...

, is directly south of the Tug Hill Plateau and receives significant lake-effect snow from Lake Ontario, averaging 115.6 inches (293.6 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
Redfield, New York
Redfield is a town in Oswego County, New York, USA. The population was 607 at the 2000 census.The Town of Redfield was incorporated from part of the Town of Mexico in 1800...

 in Oswego County and Montague
Montague, New York
Montague is a town in Lewis County, New York, United States. The population was 108 at the 2000 census. The town is named after Mary Montague Pierpont, the daughter of the original owner....

 and North Osceola
Osceola, New York
Osceola is a town in Lewis County, New York, United States. The population was 265 at the 2000 census. The town is named for the Seminole fighter, Osceola....

 in Lewis County
Lewis County, New York
As of the census of 2000, there were 26,944 people, 10,040 households, and 7,309 families residing in the county. The population density was 21 people per square mile . There were 15,134 housing units at an average density of 12 per square mile...

, 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 (358.1 cm) of snow on the Tug Hill Plateau.

A small amount of lake-effect snow from the Finger Lakes
Finger Lakes
The Finger Lakes are a pattern of lakes in the west-central section of Upstate New York in the United States. They are a popular tourist destination. The lakes are long and thin , each oriented roughly on a north-south axis. The two longest, Cayuga Lake and Seneca Lake, are among the deepest in...

 falls in upstate New York as well. The Appalachian Mountains
Appalachian Mountains
The Appalachian Mountains #Whether the stressed vowel is or ,#Whether the "ch" is pronounced as a fricative or an affricate , and#Whether the final vowel is the monophthong or the diphthong .), often called the Appalachians, are a system of mountains in eastern North America. The Appalachians...

 and Atlantic Ocean
Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...

 largely shield New York City
New York City
New York is the most populous city in the United States and the center of the New York Metropolitan Area, one of the most populous metropolitan areas in the world. New York exerts a significant impact upon global commerce, finance, media, art, fashion, research, technology, education, and...

 and Philadelphia from picking up any lake-effect snow; snow there tends to come from mesocyclonic storm systems mixing with cold temperatures.

Lake Erie
Lake Erie
Lake Erie is the fourth largest lake of the five Great Lakes in North America, and the tenth largest globally. It is the southernmost, shallowest, and smallest by volume of the Great Lakes and therefore also has the shortest average water residence time. It is bounded on the north by the...

 produces a similar effect for a zone stretching from the eastern suburbs of Cleveland through Erie
Erie, Pennsylvania
Erie is a city located in northwestern Pennsylvania in the United States. Named for the lake and the Native American tribe that resided along its southern shore, Erie is the state's fourth-largest city , with a population of 102,000...

 to Buffalo
Buffalo, New York
Buffalo is the second most populous city in the state of New York, after New York City. Located in Western New York on the eastern shores of Lake Erie and at the head of the Niagara River across from Fort Erie, Ontario, Buffalo is the seat of Erie County and the principal city of the...

. Remnants of lake-effect snows from Lake Erie have been observed to reach as far as Garrett County, Maryland
Garrett County, Maryland
Garrett County is the westernmost county of the U.S. state of Maryland. Created from Allegany County, Maryland in 1872 it was the last Maryland county to be formed. It was named for John Work Garrett , railroad executive, industrialist, and financier. Garrett served as president of the Baltimore...

. 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
Snowbelt
Snowbelt is a term describing of a number of regions near the Great Lakes in North America where heavy snowfall in the form of lake-effect snow is particularly common. Snowbelts are typically found downwind of the lakes, principally off the eastern and southern shores...

 in the United States
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 is the one in the Upper Peninsula of Michigan
Upper Peninsula of Michigan
The Upper Peninsula of Michigan is the northern of the two major land masses that make up the U.S. state of Michigan. It is commonly referred to as the Upper Peninsula, the U.P., or Upper Michigan. It is also known as the land "above the Bridge" linking the two peninsulas. The peninsula is bounded...

, near the cities of Houghton
Houghton, Michigan
Houghton is a city in the U.S. state of Michigan's Upper Peninsula and largest city in the Copper Country on the Keweenaw Peninsula. As of the 2010 census, the city population was 7,708. It is the county seat of Houghton County...

, Marquette
Marquette, Michigan
Marquette is a city in the U.S. state of Michigan and the county seat of Marquette County. The population was 21,355 at the 2010 census, making it the most populated city of the Upper Peninsula. Marquette is a major port on Lake Superior, primarily for shipping iron ore and is the home of Northern...

, and Munising
Munising, Michigan
Munising is a city on the southern shore of Lake Superior on the Upper Peninsula of the U.S. state of Michigan. As of the 2000 census, the city population was 2,539. It is the county seat of Alger County...

. These areas average 250–300 in (635–762 cm) of snow each season. For comparison, on the western shore, Duluth, Minnesota
Duluth, Minnesota
Duluth is a port city in the U.S. state of Minnesota and is the county seat of Saint Louis County. The fourth largest city in Minnesota, Duluth had a total population of 86,265 in the 2010 census. Duluth is also the second largest city that is located on Lake Superior after Thunder Bay, Ontario,...

 receives 78 inches (198.1 cm) per season. Lake Superior
Lake Superior
Lake Superior is the largest of the five traditionally-demarcated Great Lakes of North America. It is bounded to the north by the Canadian province of Ontario and the U.S. state of Minnesota, and to the south by the U.S. states of Wisconsin and Michigan. It is the largest freshwater lake in the...

 and Lake Huron
Lake Huron
Lake Huron is one of the five Great Lakes of North America. Hydrologically, it comprises the larger portion of Lake Michigan-Huron. It is bounded on the east by the Canadian province of Ontario and on the west by the state of Michigan in the United States...

 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
Keweenaw Peninsula
The Keweenaw Peninsula is the northern-most part of Michigan's Upper Peninsula. It projects into Lake Superior and was the site of the first copper boom in the United States. As of the 2000 census, its population was roughly 43,200...

 and Baraga
Baraga County, Michigan
-National protected areas:* Keweenaw National Historical Park * Ottawa National Forest -Demographics:As of the 2000 census, there were 8,746 people, 3,353 households, and 2,223 families residing in the county. The population density was 10 people per square mile . There were 4,631 housing units...

, Marquette
Marquette County, Michigan
-National protected areas:* Hiawatha National Forest * Huron National Wildlife Refuge* Ottawa National Forest -University:Northern Michigan University is a four-year university, established in 1899, located in Marquette, Michigan, on Michigan's Upper Peninsula...

 and Alger
Alger County, Michigan
Alger County is a county in the U.S. state of Michigan. As of the 2010 census, the population was 9,601. Its county seat is Munising. The Pictured Rocks National Lakeshore is located within the county.-History:...

 counties, where Lake Superior contributes to lake-effect snow, making them a prominent part of the midwestern snow belt.
Records of 390 inches (990 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
Mississippi River
The Mississippi River is the largest river system in North America. Flowing entirely in the United States, this river rises in western Minnesota and meanders slowly southwards for to the Mississippi River Delta at the Gulf of Mexico. With its many tributaries, the Mississippi's watershed drains...

 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
Rocky Mountains
The Rocky Mountains are a major mountain range in western North America. The Rocky Mountains stretch more than from the northernmost part of British Columbia, in western Canada, to New Mexico, in the southwestern United States...

. Only one official weather station exists in this region. Located in Hancock, Michigan
Hancock, Michigan
Hancock is a city in Houghton County; the northernmost in the U.S. state of Michigan, located on the Keweenaw Peninsula, or, depending on terminology, Copper Island. The population was 4,634 at the 2010 census...

, this station averages well over 210 inches per year. Farther north in the peninsula, lake-effect snow can occur with any wind direction. The road commission in Keweenaw County, Michigan
Keweenaw County, Michigan
-Demographics:As of the census of 2000, there were 2,301 people, 998 households, and 604 families residing in the county. The population density was 4 people per square mile . There were 2,327 housing units at an average density of 4 per square mile...

 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 per season. Even farther north, a ski resort called Mount Bohemia
Mount Bohemia (Michigan)
Mount Bohemia is a ski resort located near Lac La Belle, Michigan, in the northern Keweenaw peninsula. Mount Bohemia operates two chairlifts, and offers the highest vertical drop in the Midwest with 900 feet from the top of the peak to the base of the resort...

 receives an unofficial annual average of 273 inches. Herman, Michigan
Herman, Michigan
Herman is an unincorporated farming district in L'Anse Township of Baraga County in the U.S. state of Michigan. It was established in 1901 along a branch of the Duluth, South Shore and Atlantic Railway approximately midway between Nestoria and L'Anse at...

, averages 236 inches (600 cm) of snow every year. Lake-effect snow can cause blinding whiteouts
Whiteout (weather)
Whiteout is a weather condition in which visibility and contrast are severely reduced by snow or sand. The horizon disappears completely and there are no reference points at all, leaving the individual with a distorted orientation...

 in just minutes, and some storms can last days.

Western Michigan
Western Michigan
West Michigan and Western Michigan are terms for an arbitrarily selected region in the U.S. state of Michigan in its Lower Peninsula. There is no official definition for what constitutes "West Michigan." The area of West Michigan may also include parts Southern Michigan.-Definition:In general,...

, western Northern Lower Michigan
Northern Michigan
Northern Michigan, also known as Northern Lower Michigan , is a region of the U.S. state of Michigan...

, and Northern Indiana
Northern Indiana
Northern Indiana is the region of Indiana including 26 counties bordering parts of Illinois, Michigan, and Ohio. The area is generally sub-classified into other regions. The northwest is economically and culturally intertwined with Chicago, and is considered part of the Chicago metropolitan area...

 can get heavy lake-effect snows as winds pass over Lake Michigan and deposit snows over Muskegon
Muskegon, Michigan
Muskegon is a city in the U.S. state of Michigan. As of the 2010 census, the city population was 38,401. The city is the county seat of Muskegon County...

, Traverse City
Traverse City, Michigan
Traverse City is a city in the U.S. state of Michigan. It is the county seat of Grand Traverse County, although a small portion extends into Leelanau County. It is the largest city in the 21-county Northern Michigan region. The population was 14,674 at the 2010 census, with 143,372 in the Traverse...

, Grand Rapids
Grand Rapids, Michigan
Grand Rapids is a city in the U.S. state of Michigan. The city is located on the Grand River about 40 miles east of Lake Michigan. As of the 2010 census, the city population was 188,040. In 2010, the Grand Rapids metropolitan area had a population of 774,160 and a combined statistical area, Grand...

, Kalamazoo
Kalamazoo, Michigan
The area on which the modern city stands was once home to Native Americans of the Hopewell culture, who migrated into the area sometime before the first millennium. Evidence of their early residency remains in the form of a small mound in downtown's Bronson Park. The Hopewell civilization began to...

, New Carlisle
New Carlisle, Indiana
New Carlisle is a town in suburban St. Joseph County, Indiana, United States. It is located in Olive Township. The population was 1,861 at the 2010 Census...

, South Bend
South Bend, Indiana
The city of South Bend is the county seat of St. Joseph County, Indiana, United States, on the St. Joseph River near its southernmost bend, from which it derives its name. As of the 2010 Census, the city had a total of 101,168 residents; its Metropolitan Statistical Area had a population of 316,663...

, and Elkhart
Elkhart, Indiana
Elkhart is a city in Elkhart County, Indiana, United States. The city is located east of South Bend, northwest of Fort Wayne, east of Chicago, and north of Indianapolis...

, but these snows abate significantly before Lansing
Lansing, Michigan
Lansing is the capital of the U.S. state of Michigan. It is located mostly in Ingham County, although small portions of the city extend into Eaton County. The 2010 Census places the city's population at 114,297, making it the fifth largest city in Michigan...

 or Fort Wayne, Indiana
Fort Wayne, Indiana
Fort Wayne is a city in the US state of Indiana and the county seat of Allen County. The population was 253,691 at the 2010 Census making it the 74th largest city in the United States and the second largest in 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
LaPorte, Indiana
La Porte is a city in La Porte County, Indiana, United States, of which it is the county seat. Its population was 22,053 at the 2010 census. It is one of the two principal cities of the Michigan City-La Porte, Indiana Metropolitan Statistical Area, which is included in the...

 and Gary
Gary, Indiana
Gary is a city in Lake County, Indiana, United States. The city is in the southeastern portion of the Chicago metropolitan area and is 25 miles from downtown Chicago. The population is 80,294 at the 2010 census, making it the seventh-largest city in the state. It borders Lake Michigan and is known...

 Indiana
Indiana
Indiana is a US state, admitted to the United States as the 19th on December 11, 1816. It is located in the Midwestern United States and Great Lakes Region. With 6,483,802 residents, the state is ranked 15th in population and 16th in population density. Indiana is ranked 38th in land area and is...

.

Lake-effect snow is uncommon in Detroit, Milwaukee, and Chicago
Chicago
Chicago is the largest city in the US state of Illinois. With nearly 2.7 million residents, it is the most populous city in the Midwestern United States and the third most populous in the US, after New York City and Los Angeles...

, 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.

Great Lakes region, Southeast Canada

Because Southwestern Ontario is surrounded by water on three sides, many parts of Southwestern and Central Ontario get a large part of their winter snow from lake-effect snow. This region is notorious for the whiteouts which can suddenly reduce highway visibility on Canada's busiest highway from clear to zero. The region most commonly affected spans from Port Stanley
Port Stanley, Ontario
Port Stanley is a community in the Municipality of Central Elgin, Ontario, Elgin County, located on the north shore of Lake Erie at the mouth of Kettle Creek.-History:...

 in the west, Brantford and the Bruce Peninsula
Bruce Peninsula
The Bruce Peninsula is a peninsula in Ontario, Canada that lies between Georgian Bay and the main basin of Lake Huron. The peninsula extends roughly northwestwards from the rest of Southern Ontario, pointing towards Manitoulin Island, with which it forms the widest strait joining Georgian Bay to...

 in the north, Niagara-on-the-Lake
Niagara-on-the-Lake
Niagara-on-the-Lake is a Canadian town located in Southern Ontario where the Niagara River meets Lake Ontario in the Niagara Region of the southern part of the province of Ontario. It is located across the Niagara river from Youngstown, New York, USA...

 to the east, and Fort Erie
Fort Erie, Ontario
Fort Erie is a town on the Niagara River in the Niagara Region, Ontario, Canada. It is located directly across the river from Buffalo, New York....

 to the south. The heaviest accumulations usually happen in the Bruce Peninsula, which is between Lake Huron and Georgian Bay. So long as the Great Lakes are not frozen over, the only time the Bruce Peninsula does not get lake-effect snow is when the wind is directly from the south.

Toronto
Toronto
Toronto is the provincial capital of Ontario and the largest city in Canada. It is located in Southern Ontario on the northwestern shore of Lake Ontario. A relatively modern city, Toronto's history dates back to the late-18th century, when its land was first purchased by the British monarchy from...

 and Hamilton
Hamilton, Ontario
Hamilton is a port city in the Canadian province of Ontario. Conceived by George Hamilton when he purchased the Durand farm shortly after the War of 1812, Hamilton has become the centre of a densely populated and industrialized region at the west end of Lake Ontario known as the Golden Horseshoe...

 are usually spared lake-effect squalls because they are not on the leeward side of their respective lakes during the dominant northwest winds. However, northern Toronto is affected a few times each year by lake-effect snow from Georgian Bay
Georgian Bay
Georgian Bay is a large bay of Lake Huron, located entirely within Ontario, Canada...

. Downtown Toronto and Hamilton get most of their lake-effect snow when the wind comes from the southeast or east, over Lake Ontario. Such easterly winds are usually associated with a winter cyclone passing just to the south of the Great Lakes.

When the wind is from the north, the snowbelt
Snowbelt
Snowbelt is a term describing of a number of regions near the Great Lakes in North America where heavy snowfall in the form of lake-effect snow is particularly common. Snowbelts are typically found downwind of the lakes, principally off the eastern and southern shores...

 runs north-south from Grand Bend
Grand Bend, Ontario
Grand Bend, often referred to as simply "The Bend" or "GB," is a Southern Ontario community located on the shores of Lake Huron and a part of the municipality of Lambton Shores in the county of Lambton.Grand Bend is home to a variety of stores and eateries...

 to Sarnia
Sarnia, Ontario
Sarnia is a city in Southern Ontario, Canada . It is the largest city on Lake Huron and is located where the upper Great Lakes empty into the St. Clair River....

 and London
London, Ontario
London is a city in Southwestern Ontario, Canada, situated along the Quebec City – Windsor Corridor. The city has a population of 352,395, and the metropolitan area has a population of 457,720, according to the 2006 Canadian census; the metro population in 2009 was estimated at 489,274. The city...

. Areas such as Lucan and Arkona
Arkona, Ontario
Arkona is a community located in the municipality of Lambton Shores in southwestern Ontario near the Lambton-Middlesex county line, situated beside the Ausable River, on Former Kings Highway 79 , Arkona is roughly half-way between Thedford, and Watford...

 have experienced some of the heaviest snowsqualls from Lake Huron in this region. When the wind is slightly more westerly, the snowbelt runs from Tobermory
Tobermory, Ontario
Tobermory is a small community located at the northern tip of the Bruce Peninsula in the municipality of Northern Bruce Peninsula, Ontario, Canada. It is 300 km northwest of Toronto...

, Owen Sound, and Grand Bend to as far south and east as Arthur
Arthur, Ontario
Arthur is a community located just north of Hwy 6 and Wellington Road 109 in the township of Wellington North, Ontario, Canada. Formerly an independent village, Arthur was amalgamated into Wellington North on January 1, 1999.-History:...

, Orangeville
Orangeville, Ontario
Orangeville is a town in south-central Ontario, Canada, and the seat of Dufferin County.-History:Before European settlers, Orangeville was thought to be a native hunting ground...

 and Caledon
Caledon, Ontario
Caledon is a town in the Regional Municipality of Peel in the Greater Toronto Area of Ontario, Canada. In terms of land use, Caledon is somewhat urban, though it is primarily rural in nature...

. This snowbelt often reaches Kitchener
Kitchener, Ontario
The City of Kitchener is a city in Southern Ontario, Canada. It was the Town of Berlin from 1854 until 1912 and the City of Berlin from 1912 until 1916. The city had a population of 204,668 in the Canada 2006 Census...

 and can affect the Halton and Peel regions of Greater Toronto. These northwesterly winds usually also bring snow southeast of Georgian Bay, which can reach beyond Lake Scugog
Lake Scugog
Lake Scugog is an artificially flooded lake in Scugog Township between the town of Port Perry, Ontario and the town of Lindsay. The lake has been raised and lowered several times over its history. Though not technically part of the Kawarthas due to its shallow depths, it is often geographically...

. A westerly wind sends lake-effect streamers east from Owen Sound to Gravenhurst
Gravenhurst, Ontario
Gravenhurst is a town in the Muskoka Region of Ontario, Canada. It is located approximately south of Bracebridge, Ontario. The mayor is Paisley Donaldson...

, Barrie
Barrie
Barrie may refer to:* Barrie, city in Ontario, Canada* Barrie , Canadian federal electoral district* Barrie , provincial electoral district* Barrie—Simcoe—Bradford, former Canadian electoral district...

, and Orillia, and may reach as far east as York Region. When the wind is from the southwest, lake-effect streamers from Lake Huron and Georgian Bay run from Noelville to Sudbury, Gravenhurst
Gravenhurst, Ontario
Gravenhurst is a town in the Muskoka Region of Ontario, Canada. It is located approximately south of Bracebridge, Ontario. The mayor is Paisley Donaldson...

, and Algonquin Provincial Park
Algonquin Provincial Park
Algonquin Provincial Park is a provincial park located between Georgian Bay and the Ottawa River in Central Ontario, Canada, mostly within the Unorganized South Part of Nipissing District. Established in 1893, it is the oldest provincial park in Canada. Additions since its creation have increased...

. These snow bands can occasionally reach Quebec
Quebec
Quebec or is a province in east-central Canada. It is the only Canadian province with a predominantly French-speaking population and the only one whose sole official language is French at the provincial level....

 and Maine
Maine
Maine is a state in the New England region of the northeastern United States, bordered by the Atlantic Ocean to the east and south, New Hampshire to the west, and the Canadian provinces of Quebec to the northwest and New Brunswick to the northeast. Maine is both the northernmost and easternmost...

, while snow originating from Lake Erie, Lake Ontario and even Lake Michigan can impact southern Ontario. Easterly winds primarily affect the Niagara Peninsula. Local lake-effect snowsqualls can occasionally occur downwind of Lake Simcoe
Lake Simcoe
Lake Simcoe is a lake in Southern Ontario, Canada, the fourth-largest lake wholly in the province, after Lake Nipigon, Lac Seul, and Lake Nipissing. At the time of the first European contact in the 17th century the lake was called Ouentironk by the Huron natives...

 when the lake is unfrozen, usually in early winter or late fall.
Lake Superior has its own independent snowbelts, affecting Wawa
Wawa, Ontario
Wawa is a township in the Canadian province of Ontario, located within the Algoma District. Formerly known as the township of Michipicoten, the township was officially renamed for its largest and best-known community in 2009....

, Sault Ste. Marie
Sault Ste. Marie, Ontario
Sault Ste. Marie is a city on the St. Marys River in Algoma District, Ontario, Canada. It is the third largest city in Northern Ontario, after Sudbury and Thunder Bay, with a population of 74,948. The community was founded as a French religious mission: Sault either means "jump" or "rapids" in...

, Marathon
Marathon, Ontario
Marathon is a town in the Canadian province of Ontario, located in Thunder Bay District, on the north shore of Lake Superior north of Pukaskwa National Park, in the heart of the Canadian Shield.- History :...

, and Pukaskwa National Park
Pukaskwa National Park
Pukaskwa National Park is a national park located south of the town of Marathon, Ontario in the Thunder Bay District of northern Ontario, Canada. Established in 1978, Pukaskwa is known for its vistas of Lake Superior and boreal forests...

. Thunder Bay
Thunder Bay
-In Canada:Thunder Bay is the name of three places in the province of Ontario, Canada along Lake Superior:*Thunder Bay District, Ontario, a district in Northwestern Ontario*Thunder Bay, a city in Thunder Bay District*Thunder Bay, Unorganized, Ontario...

 is usually not affected by lake-effect snow, unless it is associated with a winter storm.

Elsewhere in the United States

The southern and southeastern sides of the Great Salt Lake
Great Salt Lake
The Great Salt Lake, located in the northern part of the U.S. state of Utah, is the largest salt water lake in the western hemisphere, the fourth-largest terminal lake in the world. In an average year the lake covers an area of around , but the lake's size fluctuates substantially due to its...

 receive significant lake-effect snow. Since the Great Salt Lake never freezes, the lake effect can influence the weather along the Wasatch Front
Wasatch Front
The Wasatch Front is a metropolitan region in the north-central part of the U.S. state of Utah. It consists of a chain of cities and towns stretched along the Wasatch Range from approximately Santaquin in the south to Brigham City in the north...

 year-round. The lake effect largely contributes to the 55–80 in (139.7–203.2 cm) annual snowfall amounts recorded south and east of the lake, and in average snowfall reaching 500 inches (1,270 cm) in the Wasatch Range
Wasatch Range
The Wasatch Range is a mountain range that stretches approximately from the Utah-Idaho border, south through central Utah in the western United States. It is generally considered the western edge of the greater Rocky Mountains, and the eastern edge of the Great Basin region...

. The snow, which is often very light and dry because of the semi-arid climate, is referred to as "The Greatest Snow on Earth" in the mountains. Lake-effect snow contributes to approximately 6-8 snowfalls per year in Salt Lake City, with approximately 10% of the city's precipitation being contributed by the phenomenon.

The Finger Lakes
Finger Lakes
The Finger Lakes are a pattern of lakes in the west-central section of Upstate New York in the United States. They are a popular tourist destination. The lakes are long and thin , each oriented roughly on a north-south axis. The two longest, Cayuga Lake and Seneca Lake, are among the deepest in...

 of New York
New York
New York is a state in the Northeastern region of the United States. It is the nation's third most populous state. New York is bordered by New Jersey and Pennsylvania to the south, and by Connecticut, Massachusetts and Vermont to the east...

 are long enough for lake-effect precipitation. The Texas
Texas
Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...

 twin cities of Sherman
Sherman, Texas
Sherman is a city in and the county seat of Grayson County, Texas, United States. The city's estimated population as of 2009 was 38,407. It is also one of two principal cities in the Sherman-Denison Metropolitan Statistical Area.-History:...

 and Denison
Denison, Texas
Denison is a city in Grayson County, Texas, United States. The population was 22,773 at the 2000 census; it is estimated to have grown to 24,127 in 2009. Denison is one of two principal cities in the Sherman-Denison Metropolitan Statistical Area.-History:...

 are known to have experienced lake-effect snow from Lake Texoma
Lake Texoma
Lake Texoma is one of the largest reservoirs in the United States, the 12th largest Corps of Engineers lake, and the largest in USACE Tulsa District....

 in rare instances.

The Truckee Meadows
Truckee Meadows
The Truckee Meadows is a valley in Northern Nevada which contains the cities of Reno and Sparks. The valley is approximately 10 miles square.Truckee Meadows is bounded by the Carson Range in the west and the Virginia Range in the east...

 and other parts of Northern Nevada which are normally in the rain shadow
Rain shadow
A rain shadow is a dry area on the lee side of a mountainous area. The mountains block the passage of rain-producing weather systems, casting a "shadow" of dryness behind them. As shown by the diagram to the right, the warm moist air is "pulled" by the prevailing winds over a mountain...

 of the Sierra Nevada can, when conditions are right, have severe snowfall as a result of lake effect from Lake Tahoe
Lake Tahoe
Lake Tahoe is a large freshwater lake in the Sierra Nevada of the United States. At a surface elevation of , it is located along the border between California and Nevada, west of Carson City. Lake Tahoe is the largest alpine lake in North America. Its depth is , making it the USA's second-deepest...

. Recent severe examples of this phenomenon have occurred as recently as 2004, dumping several feet of snow in the normally dry region.

The West Coast
West Coast of the United States
West Coast or Pacific Coast are terms for the westernmost coastal states of the United States. The term most often refers to the states of California, Oregon, and Washington. Although not part of the contiguous United States, Alaska and Hawaii do border the Pacific Ocean but can't be included in...

 occasionally experiences ocean-effect showers, usually in the form of rain at lower elevations south of about the mouth of the Columbia River
Columbia River
The Columbia River is the largest river in the Pacific Northwest region of North America. The river rises in the Rocky Mountains of British Columbia, Canada, flows northwest and then south into the U.S. state of Washington, then turns west to form most of the border between Washington and the state...

. These occur whenever an Arctic air mass from western Canada is drawn westward out over the Pacific Ocean, typically by way of the Fraser Valley
Fraser Valley
The Fraser Valley is the section of the Fraser River basin in southwestern British Columbia downstream of the Fraser Canyon. The term is sometimes used to refer to the Fraser Canyon and stretches upstream from there, but in general British Columbian usage of the term refers to the stretch of the...

, returning shoreward around a center of low pressure. Cold air flowing southwest from the Fraser Valley can also pick up moisture over the Strait of Georgia
Strait of Georgia
The Strait of Georgia or the Georgia Strait is a strait between Vancouver Island and the mainland coast of British Columbia, Canada. It is approximately long and varies in width from...

 and Strait of Juan de Fuca
Strait of Juan de Fuca
The Strait of Juan de Fuca is a large body of water about long that is the Salish Sea outlet to the Pacific Ocean...

, then rise over the northeastern slopes of the Olympic Mountains
Olympic Mountains
The Olympic Mountains is a mountain range on the Olympic Peninsula of western Washington in the United States. The mountains, part of the Pacific Coast Ranges, are not especially high - Mount Olympus is the highest at - but the western slopes of the Olympics rise directly out of the Pacific...

, producing heavy, localized snow between Port Angeles
Port Angeles, Washington
Port Angeles is a city in and the county seat of Clallam County, Washington, United States. The population was 19,038 at the 2010 census. The area's harbor was dubbed Puerto de Nuestra Señora de los Ángeles by Spanish explorer Francisco de Eliza in 1791, but by the mid-19th century the name had...

 and Sequim
Sequim, Washington
Sequim is a city in Clallam County, Washington, United States. The 2010 US Census counted a population of 6,606. Sequim is located along the Dungeness River near the base of the Olympic Mountains...

, as well as areas in Kitsap County
Kitsap County, Washington
Kitsap County is a county located in the U.S. state of Washington, named after Chief Kitsap of the Suquamish tribe. As of 2011 state estimate, its population was 253,900. Its county seat is at Port Orchard, and its largest city is Bremerton....

 and the Puget Sound region
Puget Sound region
The Puget Sound region is an inland area of the Pacific Northwest in Washington , including Puget Sound, the Puget Sound lowlands, and the surrounding region roughly west of the Cascade Range and east of the Olympic Mountains.- History :...

.

Rarely, the phenomenon of gulf-effect snow has been observed along the northern coast of the Gulf of Mexico
Gulf of Mexico
The Gulf of Mexico is a partially landlocked ocean basin largely surrounded by the North American continent and the island of Cuba. It is bounded on the northeast, north and northwest by the Gulf Coast of the United States, on the southwest and south by Mexico, and on the southeast by Cuba. In...

, notably during Florida
Florida
Florida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...

's Great Blizzard of 1899
Great Blizzard of 1899
The Great Blizzard of 1899 was an unprecedented winter weather event that affected the southern United States. What made it historic was both the severity of winter weather and the extent of the U.S. it affected, especially in the South. The first reports indicated record-high barometric pressure...

.

Elsewhere in Canada

Lake Winnipeg
Lake Winnipeg
Lake Winnipeg is a large, lake in central North America, in the province of Manitoba, Canada, with its southern tip about north of the city of Winnipeg...

 and Lake Winnipegosis
Lake Winnipegosis
Lake Winnipegosis is a large lake in central North America, in Manitoba, Canada, some 300 km northwest of Winnipeg. It is Canada's eleventh-largest lake...

 in Manitoba
Manitoba
Manitoba is a Canadian prairie province with an area of . The province has over 110,000 lakes and has a largely continental climate because of its flat topography. Agriculture, mostly concentrated in the fertile southern and western parts of the province, is vital to the province's economy; other...

 traditionally see lake-effect snow as early as late October, and it is common throughout early to mid November. Towards the end of November the lakes sufficiently cool and begin to freeze ending the lake effect snow. A brief period of lake-effect snow is also common near Great Bear Lake
Great Bear Lake
Great Bear Lake is the largest lake entirely within Canada , the third or fourth largest in North America, and the seventh or eighth largest in the world...

 and Great Slave Lake
Great Slave Lake
Great Slave Lake is the second-largest lake in the Northwest Territories of Canada , the deepest lake in North America at , and the ninth-largest lake in the world. It is long and wide. It covers an area of in the southern part of the territory. Its given volume ranges from to and up to ...

 in the Northwest Territories
Northwest Territories
The Northwest Territories is a federal territory of Canada.Located in northern Canada, the territory borders Canada's two other territories, Yukon to the west and Nunavut to the east, and three provinces: British Columbia to the southwest, and Alberta and Saskatchewan to the south...

 during early winter (usually early to mid October); however the lake-effect season for both lakes is very short. The lakes are frozen roughly 8 months of the year and as a result have very little time to warm during the summer months.

Other small lakes such as Lake Athabasca
Lake Athabasca
Lake Athabasca is located in the northwest corner of Saskatchewan and the northeast corner of Alberta between 58° and 60° N.-History:The name in the Dene language originally referred only to the large delta formed by the confluence the Athabasca River at the southwest corner of the lake...

 in northern Saskatchewan
Saskatchewan
Saskatchewan is a prairie province in Canada, which has an area of . Saskatchewan is bordered on the west by Alberta, on the north by the Northwest Territories, on the east by Manitoba, and on the south by the U.S. states of Montana and North Dakota....

 and Lake Nipigon
Lake Nipigon
Lake Nipigon is the largest lake entirely within the boundaries of the Canadian province of Ontario . It is sometimes described as the sixth Great Lake. Lying 260 metres above sea level, the lake drains into the Nipigon River and thence into Nipigon Bay of Lake Superior...

 in northwestern Ontario
Ontario
Ontario is a province of Canada, located in east-central Canada. It is Canada's most populous province and second largest in total area. It is home to the nation's most populous city, Toronto, and the nation's capital, Ottawa....

 produce early season lake-effect snows. The Smallwood Reservoir
Smallwood Reservoir
The Smallwood Reservoir is a large reservoir located in the western part of Labrador in the province of Newfoundland and Labrador, Canada. The reservoir is the source of the Churchill River. Unlike other reservoirs, water is contained not by a single large dam, but by a series of 88 dikes that...

, a man-made lake located in Labrador
Labrador
Labrador is the distinct, northerly region of the Canadian province of Newfoundland and Labrador. It comprises the mainland portion of the province, separated from the island of Newfoundland by the Strait of Belle Isle...

 has on occasion generated lake-effect snow.

Similar phenomena

Similar snowfall can occur near large inland bays, where it is known as bay-effect snow. Bay-effect snows fall downwind of Delaware Bay
Delaware Bay
Delaware Bay is a major estuary outlet of the Delaware River on the Northeast seaboard of the United States whose fresh water mixes for many miles with the waters of the Atlantic Ocean. It is in area. The bay is bordered by the State of New Jersey and the State of Delaware...

, Chesapeake Bay
Chesapeake Bay
The Chesapeake Bay is the largest estuary in the United States. It lies off the Atlantic Ocean, surrounded by Maryland and Virginia. The Chesapeake Bay's drainage basin covers in the District of Columbia and parts of six states: New York, Pennsylvania, Delaware, Maryland, Virginia, and West...

, and Massachusetts Bay
Massachusetts Bay
The Massachusetts Bay, also called Mass Bay, is one of the largest bays of the Atlantic Ocean which forms the distinctive shape of the coastline of the U.S. state of Massachusetts. Its waters extend 65 miles into the Atlantic Ocean. Massachusetts Bay includes the Boston Harbor, Dorchester Bay,...

 when the basic criteria are met. Ocean-effect snows are possible downwind of the Gulf Stream
Gulf Stream
The Gulf Stream, together with its northern extension towards Europe, the North Atlantic Drift, is a powerful, warm, and swift Atlantic ocean current that originates at the tip of Florida, and follows the eastern coastlines of the United States and Newfoundland before crossing the Atlantic Ocean...

 and the Sea of Japan
Sea of Japan
The Sea of Japan is a marginal sea of the western Pacific Ocean, between the Asian mainland, the Japanese archipelago and Sakhalin. It is bordered by Japan, North Korea, Russia and South Korea. Like the Mediterranean Sea, it has almost no tides due to its nearly complete enclosure from the Pacific...

. Canadian Maritimes
Maritimes
The Maritime provinces, also called the Maritimes or the Canadian Maritimes, is a region of Eastern Canada consisting of three provinces, New Brunswick, Nova Scotia, and Prince Edward Island. On the Atlantic coast, the Maritimes are a subregion of Atlantic Canada, which also includes the...

, in particular Nova Scotia
Nova Scotia
Nova Scotia is one of Canada's three Maritime provinces and is the most populous province in Atlantic Canada. The name of the province is Latin for "New Scotland," but "Nova Scotia" is the recognized, English-language name of the province. The provincial capital is Halifax. Nova Scotia is the...

 and Prince Edward Island
Prince Edward Island
Prince Edward Island is a Canadian province consisting of an island of the same name, as well as other islands. The maritime province is the smallest in the nation in both land area and population...

 provinces, are often affected by such snow squalls when an Arctic winter airmass moves over unfrozen waters. This effect is especially intense with very warm waters of the Gulf Stream
Gulf Stream
The Gulf Stream, together with its northern extension towards Europe, the North Atlantic Drift, is a powerful, warm, and swift Atlantic ocean current that originates at the tip of Florida, and follows the eastern coastlines of the United States and Newfoundland before crossing the Atlantic Ocean...

 or the Sea of Japan
Sea of Japan
The Sea of Japan is a marginal sea of the western Pacific Ocean, between the Asian mainland, the Japanese archipelago and Sakhalin. It is bordered by Japan, North Korea, Russia and South Korea. Like the Mediterranean Sea, it has almost no tides due to its nearly complete enclosure from the Pacific...

. This also happens usually a couple of times per winter in the area near Cape Cod
Cape Cod
Cape Cod, often referred to locally as simply the Cape, is a cape in the easternmost portion of the state of Massachusetts, in the Northeastern United States...

, and on rarer occasions along Long Island
Long Island
Long Island is an island located in the southeast part of the U.S. state of New York, just east of Manhattan. Stretching northeast into the Atlantic Ocean, Long Island contains four counties, two of which are boroughs of New York City , and two of which are mainly suburban...

. An extreme occurrence of "ocean effect" snow occurred on January 24, 2003, when wind off the Atlantic, combined with air temperatures in the 20 °F (-6.7 °C), brought snow flurries to the Atlantic coast of Florida
Florida
Florida is a state in the southeastern United States, located on the nation's Atlantic and Gulf coasts. It is bordered to the west by the Gulf of Mexico, to the north by Alabama and Georgia and to the east by the Atlantic Ocean. With a population of 18,801,310 as measured by the 2010 census, it...

 as far south as Cape Canaveral
Cape Canaveral
Cape Canaveral, from the Spanish Cabo Cañaveral, is a headland in Brevard County, Florida, United States, near the center of the state's Atlantic coast. Known as Cape Kennedy from 1963 to 1973, it lies east of Merritt Island, separated from it by the Banana River.It is part of a region known as the...

.

International

Lake-effect snow occurs in other countries, near large lakes or large sea areas. One such example is the Aegean Sea
Aegean Sea
The Aegean Sea[p] is an elongated embayment of the Mediterranean Sea located between the southern Balkan and Anatolian peninsulas, i.e., between the mainlands of Greece and Turkey. In the north, it is connected to the Marmara Sea and Black Sea by the Dardanelles and Bosporus...

 in Greece
Greece
Greece , officially the Hellenic Republic , and historically Hellas or the Republic of Greece in English, is a country in southeastern Europe....

, where cold northeast winds known as the boreas combined with the sea moisture can produce snowfalls over western portions of Attica province, the island of Euboea
Euboea
Euboea is the second largest Greek island in area and population, after Crete. The narrow Euripus Strait separates it from Boeotia in mainland Greece. In general outline it is a long and narrow, seahorse-shaped island; it is about long, and varies in breadth from to...

 and mount Pilio area. It also occurs in the regions of the Black Sea in Georgia
Georgia (country)
Georgia is a sovereign state in the Caucasus region of Eurasia. Located at the crossroads of Western Asia and Eastern Europe, it is bounded to the west by the Black Sea, to the north by Russia, to the southwest by Turkey, to the south by Armenia, and to the southeast by Azerbaijan. The capital of...

 and Turkey
Turkey
Turkey , known officially as the Republic of Turkey , is a Eurasian country located in Western Asia and in East Thrace in Southeastern Europe...

 or the Adriatic Sea
Adriatic Sea
The Adriatic Sea is a body of water separating the Italian Peninsula from the Balkan peninsula, and the system of the Apennine Mountains from that of the Dinaric Alps and adjacent ranges...

 and Italy
Italy
Italy , officially the Italian Republic languages]] under the European Charter for Regional or Minority Languages. In each of these, Italy's official name is as follows:;;;;;;;;), is a unitary parliamentary republic in South-Central Europe. To the north it borders France, Switzerland, Austria and...

. For example, this type of precipitation which was generated by warmer Black Sea
Black Sea
The Black Sea is bounded by Europe, Anatolia and the Caucasus and is ultimately connected to the Atlantic Ocean via the Mediterranean and the Aegean seas and various straits. The Bosphorus strait connects it to the Sea of Marmara, and the strait of the Dardanelles connects that sea to the Aegean...

 and colder air temperature, was seen in the Istanbul
Istanbul
Istanbul , historically known as Byzantium and Constantinople , is the largest city of Turkey. Istanbul metropolitan province had 13.26 million people living in it as of December, 2010, which is 18% of Turkey's population and the 3rd largest metropolitan area in Europe after London and...

 area between 24 and 26 January 2010. The snowfall in the eastern regions of the Black Sea is amplified by the orographic effect of the nearby Caucasus Mountains
Caucasus Mountains
The Caucasus Mountains is a mountain system in Eurasia between the Black Sea and the Caspian Sea in the Caucasus region .The Caucasus Mountains includes:* the Greater Caucasus Mountain Range and* the Lesser Caucasus Mountains....

, often resulting in snowfall of several meters, especially at higher elevations. In Northern Europe
Northern Europe
Northern Europe is the northern part or region of Europe. Northern Europe typically refers to the seven countries in the northern part of the European subcontinent which includes Denmark, Estonia, Latvia, Lithuania, Norway, Finland and Sweden...

, cold, dry air masses from Russia
Russia
Russia or , officially known as both Russia and the Russian Federation , is a country in northern Eurasia. It is a federal semi-presidential republic, comprising 83 federal subjects...

 can blow over the Baltic Sea
Baltic Sea
The Baltic Sea is a brackish mediterranean sea located in Northern Europe, from 53°N to 66°N latitude and from 20°E to 26°E longitude. It is bounded by the Scandinavian Peninsula, the mainland of Europe, and the Danish islands. It drains into the Kattegat by way of the Øresund, the Great Belt and...

 and cause heavy snow squalls on areas of the southern and eastern coasts of Sweden
Sweden
Sweden , officially the Kingdom of Sweden , is a Nordic country on the Scandinavian Peninsula in Northern Europe. Sweden borders with Norway and Finland and is connected to Denmark by a bridge-tunnel across the Öresund....

.

In the United Kingdom
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...

, easterly winds bringing cold continental air across the North Sea
North Sea
In the southwest, beyond the Straits of Dover, the North Sea becomes the English Channel connecting to the Atlantic Ocean. In the east, it connects to the Baltic Sea via the Skagerrak and Kattegat, narrow straits that separate Denmark from Norway and Sweden respectively...

 can lead to a similar phenomenon. Locally it is also known as "lake-effect snow" despite the snow coming in from the sea rather than a lake. Similarly during a north-westerly wind, snow showers can form coming in from the Liverpool Bay
Liverpool Bay
Liverpool Bay is a bay of the Irish Sea between northeast Wales, Cheshire, Lancashire and Merseyside to the east of the Irish Sea. The bay is a classic example of a region of freshwater influence...

, coming down the Cheshire gap
Cheshire Plain
The Cheshire Plain is a relatively flat expanse of lowland situated almost entirely within the county of Cheshire in northwest England. It is bounded by the hills of North Wales to the west, and the Peak District of Derbyshire and North Staffordshire to the east and southeast...

, causing snowfall in the West Midlands
West Midlands (region)
The West Midlands is an official region of England, covering the western half of the area traditionally known as the Midlands. It contains the second most populous British city, Birmingham, and the larger West Midlands conurbation, which includes the city of Wolverhampton and large towns of Dudley,...

 - this formation resulted in the white Christmas of 2004, in the area. A similar phenomenon can affect the city of Inverness
Inverness
Inverness is a city in the Scottish Highlands. It is the administrative centre for the Highland council area, and is regarded as the capital of the Highlands of Scotland...

 in the Scottish Highlands
Scottish Highlands
The Highlands is an historic region of Scotland. The area is sometimes referred to as the "Scottish Highlands". It was culturally distinguishable from the Lowlands from the later Middle Ages into the modern period, when Lowland Scots replaced Scottish Gaelic throughout most of the Lowlands...

, where cold north east winds cause heavy snow to form in the Moray Firth
Moray Firth
The Moray Firth is a roughly triangular inlet of the North Sea, north and east of Inverness, which is in the Highland council area of north of Scotland...

; this was the case with the White Hogmanay of 2009, which caused the street party to be cancelled. Northerly and north-westerly winds can cause the effect to occur over the Irish Sea
Irish Sea
The Irish Sea separates the islands of Ireland and Great Britain. It is connected to the Celtic Sea in the south by St George's Channel, and to the Atlantic Ocean in the north by the North Channel. Anglesey is the largest island within the Irish Sea, followed by the Isle of Man...

 and Bristol Channel
Bristol Channel
The Bristol Channel is a major inlet in the island of Great Britain, separating South Wales from Devon and Somerset in South West England. It extends from the lower estuary of the River Severn to the North Atlantic Ocean...

 feeding snow into south-west England.

Since the North Sea is relatively warm (around 13C at the beginning of winter, typically 10C to 6C by the end), sufficiently cold air aloft can create significant snowfalls in a relatively short period of time. The best-known example occurred in January 1987, when record-breaking cold air (associated with an upper low) moved across the North Sea towards the UK. The end result was over a foot of snow for coastal areas, leading to communities being cut off for over a week. In recent years, lake-effect snow has been much lighter.

The Sea of Japan creates snowfall in the mountainous western Japanese prefectures of Niigata and Nagano, parts of which are known collectively as Snow country
Snow country (Japan)
Snow country refers to areas in Japan characterized by heavy, long-lasting snowfalls....

 ("Yukiguni").

See also

  • Great Salt Lake effect
    Great Salt Lake effect
    The Great Salt Lake effect is a small but detectable influence on the local climate and weather around the Great Salt Lake in Utah, United States. In particular, snowstorms are a common occurrence over the region and have major socio-economic impacts due to their significant precipitation amounts...

  • Horizontal convective rolls
    Horizontal convective rolls
    Horizontal convective rolls, also known as horizontal roll vortices or cloud streets, are long rolls of counter-rotating air that are oriented approximately parallel to the ground in the planetary boundary layer...

  • Lake effect blizzard
    Lake effect blizzard
    Lake effect blizzard is an unofficial term used to describe blizzard-like conditions resulting from lake-effect snow.- Formation and usage :Under certain conditions strong winds can accompany lake-effect snows creating blizzard-like conditions...

  • Planetary boundary layer
    Planetary boundary layer
    The planetary boundary layer , also known as the atmospheric boundary layer , is the lowest part of the atmosphere and its behavior is directly influenced by its contact with a planetary surface. On Earth it usually responds to changes in surface forcing in an hour or less...

  • Sea smoke
    Sea smoke
    Sea smoke, or arctic steam fog, is a cloud over the sea, which could otherwise be called fog, and is usually formed when very cold air moves over warmer water. The physics are in principle similar to lake-effect snow....



Warnings about lake-effect snow:

United States:
  • Lake Effect Snow Advisory
    Lake Effect Snow Advisory
    A Lake Effect Snow Advisory is issued by the National Weather Service of the United States when lake effect snow may pose a hazard or is life threatening. The snow must be completely caused by a convective snow development over a lake and not by a low pressure system...

  • Lake Effect Snow Warning
    Lake Effect Snow Warning
    A Lake Effect Snow Warning is a bulletin issued by the National Weather Service in the United States to warn of heavy snowfall amounts that are imminent from convective snow generated by very cold airmass passing over unfrozen lakes...

  • Severe weather terminology (United States)
    Severe weather terminology (United States)
    This article describes the United States National Weather Service severe weather terminology. The NWS defines precise meanings for nearly all its weather terms. This article describes NWS terminology and related NWS weather scales...



Canada:
  • Snowsquall warning
    Snowsquall warning
    Snowsquall warning is a bulletin issued by Environment Canada's Meteorological Service of Canada to warn population of two types of snow events reducing visibilities in blowing snow:...

  • Severe weather terminology (Canada)
    Severe weather terminology (Canada)
    This article describes Severe weather Terminology used by the Environment Canada's Meteorological Service of Canada. This article primarily describes various weather warnings, and their criteria. Related weather scales and general weather terms are also addressed in this article...


External links

The source of this article is wikipedia, the free encyclopedia.  The text of this article is licensed under the GFDL.
 
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