An Alberta clipper is a fast-moving low pressure system moving southeast of the Canadian province of Alberta through the plains and Midwest.

While an Alberta clipper can appear any time between October and March, they are most common during the winter months. They usually bring snow, strong winds and cold temperatures.

Once the clipper moves from Alberta to the East Coast, the system is sometimes fueled by moisture from the Atlantic Ocean. This will cause the system to quickly intensify and spread heavy snow across New England.

Clippers in Alberta can produce wind speeds of up to 60 miles per hour. These gusty winds, combined with heavy snowfall, can quickly turn into blizzards in areas where the snow is heaviest or where there is already a loose blanket of snow on the ground.

Areas affected by Alberta clippers may experience drastic temperature fluctuations that may persist for days after the clippers move on. It’s not uncommon for temperatures to drop 30 degrees in just 12 hours. The freezing Canadian air brought by the Alberta Clipper can lead to dangerously low wind chill temperatures, and its rapid heavy snowfall can cause havoc for travelers.

Less than 10% of Alberta’s clipper systems run south of the Great Lakes. For this reason they cannot take advantage of southern moisture. Due to the lack of moisture and the speed of movement (Alberta clippers typically move at 30-40 miles per hour), these systems are not typically blockbuster snow guns. But not always.

La Niña has a major impact on the Clippers in Alberta. During a La Niña year, the jet stream dives southward over the Great Lakes. This will allow much colder air to flow south, which can increase lake effect snow. If this happens, a clipper ship’s snowfall in Alberta could be significantly higher.

(MORE: What is Lake Effect Snow? ​| What is La Nina?).​

“If both the jet stream disturbance and cold front are strong, Alberta Clippers may also produce short, severe bursts known as snow squalls,” Erdman said. “These can severely restrict visibility and quickly make roads slippery, leading to dangerous driving conditions.”

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There are two other variants of the Alberta Clipper. The Saskatchewan Screamer and the Manitoba Mauler are also clipper systems. The only difference is the position from which they dive south. The Saskatchewan Screamer begins its journey south in the Canadian province of Saskatchewan, while the Manitoba Mauler dives south from the Province of Manitoba.

Jennifer Grey is a weather and climate writer for Weather.com. She has been reporting on some of the world’s biggest weather and climate stories for two decades.