The Weather Network – Buried: Why the Great Lakes produce some of the world’s heaviest snow

Snow fell from the sky for three days in a row.

The cold winds blowing over Lake Erie unleashed a disaster that will destroy hundreds of homes and businesses, shut down entire cities for days, and even force a mother-to-be to give birth at a firehouse because no vehicles could take her to the hospital.

PODCAST: State of emergency declared over 2014 great buffalo blizzard

On November 17, 2014, a solid layer of lake-like snow rolled over western New York. This unwavering squall was as torrential as it was persistent, producing blizzards that eventually subsided until November 19.

This all-day lake-effect snow phenomenon produced as much as 165 cm of snow near Buffalo, New York, burying some homes up to the second floor and immobilizing the area for days.

The lake-effect snow disaster in western New York highlighted one basic fact of living near lakes during the cold season: snow squalls are not something to sneeze at.

Lake-effect snow and summer thunderstorms are cousins

Lake-effect snow has its own distinctive effect because it is formed by the same process that causes a thunderstorm on a humid summer afternoon.

snow ingredients with lake effect

Snow squalls from lakes are a product of convection. We experience most lake-effect snow in the fall and early winter because there is still a large temperature difference between the surface of the lakes and the much cooler winds blowing over the water.

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Some of this air comes in direct contact with the warmer waters, heating up this shallow layer of air, like a camper holding his hands over a fire to keep warm. This air becomes warmer than its surroundings, which allows it to start rising in the atmosphere.

The greater difference between the temperature of the lake and the atmosphere above will cause the air to rise even faster, producing snowfall, much like thunderstorms on a hot July day.

SEE: How lake-like snow forms over a warm lake

A dangerous fetch game

If you can’t stand the snow, you don’t want fetching to happen.

Fetch is the distance the wind travels in open water. A longer download means the wind spends more time and travels a greater distance over the water, which is a key ingredient in lake-like snow formation.

Strong winds blowing over the water organize these snowfalls into bands, blowing them over the shores of the lake and giving us the lake effect that is so well known in the run-up to the holiday season.

Meteorologists are watching the wind direction closely to get clues about where the snow bands will form and how heavy they might grow.

A short fetch leads to many but narrow bands of snow that can cover a large area with a modest blanket of accumulation. On the other hand, a long download leads to single, thick strips of snow.

The Great Lakes are king, but it’s a common problem

The size, depth, and location of the Great Lakes make the region the prime location for lake-effect snow, but the phenomenon is possible throughout Canada and around the world.

snow belt with lake effect

Lake-effect snow is common in southern Manitoba in the early fall before the lakes freeze over. Sea-effect snow – which is formed by the same process, right over the ocean – is a regular sight during the cold season in the Atlantic provinces.

We even see lake and sea effect snow all over the world. Sapporo, Japan is one of the snowiest cities in the world due to the sea-effect snow that covers the city of nearly two million people meter by meter of powder each season.

The prevailing winds make some parts of the Great Lakes more prone to these snow hits than others. Northwesterly winds blowing over Lake Huron and Georgian Bay leave communities like Kincardine, Goderich, and Barrie open to heavy snowpacks.

Lake Erie and Lake Ontario are famous for their fire hose-like lanes of snow shedding across the Niagara Region, eastern Ontario, and western New York, as southwesterly winds reach exceptionally long gusts along the entire length of these lakes, feeding intense snow bands that can last many days.

SEE: Why it’s so hard to predict snow storms

Terrifying intensity meets the edge of a knife

These legendary snow bands can produce some of the most intense winter conditions you’ll ever experience on the planet, resembling a violent winter storm.

The most powerful lake effect events can produce snowfalls in excess of 10 cm per hour, overwhelming the ability of plows to keep roads clear for more than a few minutes at a time. Convection strong enough to produce this kind of breaking snowfall often leads to flashy lightning and loud thunder.

(NY State Police/Facebook) A snow-covered highway in Buffalo, November 2014Several feet of snow covers the New York State Thruway near Buffalo, NY during a November 2014 lake-effect snowstorm. (New York State Police/Facebook)

What’s more terrifying than hours of blizzards and heavy snowfall is that these streaks can be very hard to predict.

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Snow squalls are often so narrow that a few kilometers mean the difference between a serene winter scenery and a nightmarish disaster that shuts down entire neighborhoods for days.

Only a slight change in wind direction or a slight fluctuation in the band itself can change these gigantic amounts of snow along with it. Snow mounds that fell south of Buffalo in 2014 would have hit the center of the city itself if the range had moved just a few miles further north.

Image thumbnail courtesy of Pixabay.

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