The polar vortex, as its name suggests, is found around the North Pole. It’s a band of strong winds, high in the atmosphere, keeping bitterly cold air locked around the Arctic region.

Snowy Oak Tree by Scott Stringham of Rustling Leaf Design
Snowy Oak Tree by Scott Stringham of Rustling Leaf Design

The circulation as such is not considered a single storm, or even a pattern of weather. The North Pole polar vortex expands during the winter, sending cold air to the south; this occurs regularly and is often associated with cold temperature outbreaks in the U.S.

In the past couple of years the term “polar vortex” has become more commonly used, but the phenomenon has been around forever.

Mark Chenard, National Weather Service Meteorologist, Interview with Reuters

Is Polar Vortex linked to climate change?

Studies have shown a recent rise in cases where the polar vortex has sprouted into densely populated areas. Scientists gain a better understanding of why this is happening, with many identifying as influencing climate change.

There is evidence that as the planet warms, the jet stream, a meandering air stream flowing across North America and Europe, slows down and becomes wavier. The jet stream interacts with the powerful polar vortex, contributing to further southward numbing temperatures.

Also, scientists point to a complex chain of events involving sea ice, which is declining rapidly in the Arctic. As the ice retreats, the dark ocean below absorbs summer heat. During the winter, this heat is released into the atmosphere, spurring winds that can interfere with the polar vortex.

Do we need a robust polar vortex to stay warm?

In 2014, when a brutal January cold snapped sending the country into a deep freeze, the term “polar vortex” became popular. Babbitt, Minnesota, was -37 ° low. New York City’s 4 ° low broke a record of 118 years, but while the name sounds dramatic, there’s nothing out of the ordinary or all that new about the polar vortex.

When meteorologists talk about the “polar vortex,” they talk about the cold, low-pressure air mass that is constantly floating over the Arctic. It is called a “vortex” because, like a hurricane, it spins counterclockwise.  National Weather Service on its website emphasizes that “It ALWAYS exists near the poles.” The mass of cold polar air usually remains over the North Pole; well, because it is usually strong, centered, and compact. However, the vortex weakens sometimes, and a weak vortex means colder weather in the mid-latitudes as the vortex lobes begin to shrink away from the Arctic region.

Related Article: “Winter Storms: The Ultimate Challenge”

The weak vortex influences the jet stream path, an area high in the atmosphere of fast-moving air, a weak vortex can cause the south wobbling of the jet stream, bringing down the cold polar air.

The breaking off of the vortex part is what defines an event of a polar vortex, but when the vortex is weaker, not stronger, it happens; this might sound strange — but it makes sense. Usually, when the vortex is strong and healthy, it helps to keep in a pretty circular path a current of air known as the jet stream that travels around the globe. The current keeps north the cold air and south the warm air, but the jet stream isn’t strong enough to keep in line without that strong low-pressure system.

When it gets wavy and rambling, putting a few areas of high-pressure systems in its way, and all of a sudden, along with the rest of the polar vortex system, you have a river of cold air pushed down south.

Diagram of a regular polar vortex system and a polar vortex event showing jetstream and low and high pressure systems.

The science behind the polar vortex.(NOAA)

That was what occurred in early 2014. The polar vortex suddenly weakened, and a vast high-pressure system formed Greenland. The high-pressure system blocked the jet stream’s escape from all that cold air, allowing a portion of the polar vortex to move southward.  The state of Florida experienced the wrath of this out of control polar vortex in places as far south as Tampa, Florida. At the height of this cold snap, most of Canada and parts of the Midwestern United States had colder temperatures than Alaska!

The result of the polar vortex is not all about cold weather.  While the weather beast is usually found in the north, it is solitary. Extremely unusual weather conditions will need to occur for the polar vortex to weaken or migrate far south.  While on it’s way south the polar vortex causes cold arctic air to travel our way.

References:

What Is A Polar Vortex? | Noaa Scijinks – All About Weather. (n.d.). Retrieved from https://scijinks.gov/polar-vortex/

The Polar Vortex, Briefly Explained – Vox. (n.d.). Retrieved from https://www.vox.com/science-and-health/2019/1/29/18201196/polar-vortex-2019-des-

About the Author:

This blog was written by Linda Rawson, who is the founder of DynaGrace Enterprises (dynagrace.com) and the inventor of WeatherEgg (weatheregg.com). For further information, please connect with Linda on LinkedIn, or contact her at (800) 676-0058 ext 101.

To help kids with Weather Linda has created coloring books in four different languages. WeatherEgg Kids: Weather from A-Z: Coloring Book (https://amzn.to/2HMhOgp), WeatherEgg Kids: Palabras del clima: Libro de colorear (https://amzn.to/2I2c7KK), WeatherEgg Kids: Wetter Worte: Malbuch (https://amzn.to/2YFuf31), and WeatherEgg Kids: Les mots de la meteo: Livre de coloriage (https://amzn.to/2HZGAcd)

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