Buzz
If you've been watching the news or stepping outside recently, you're likely aware of the extreme cold that has taken hold across much of North America. As reported by The Washington Post, a blast of icy air over Canada—known as a polar vortex—split into three segments at the start of 2019, with one heading towards the eastern United States. Polar vortexes have the ability to send freezing Arctic air straight from the tundra into milder climates. But what exactly is this weather phenomenon?
How is a polar vortex created?
Polar vortexes are essentially arctic storms or cyclones. According to NASA, they are “a whirling and persistent large area of low pressure, found typically over both North and South poles.” These wintertime occurrences develop as the sun sets over the pole and temperatures drop, typically forming in the middle and upper layers of the atmosphere (the troposphere and stratosphere, around six to 31 miles above the Earth’s surface).
Where is a polar vortex likely to strike?
In the Northern Hemisphere, polar vortexes spin in a counterclockwise motion. While they usually dip over Canada, according to NBC News, they can sometimes move into the lower 48 states if warm conditions over Greenland or Alaska push denser, colder air southward, or due to other atmospheric shifts.
Polar vortexes aren’t uncommon—in fact, Arctic winds occasionally make their way into the eastern U.S. But when they do, the scale of the area impacted can be much larger than usual.
How freezing is a polar vortex?
So cold that frozen sharks have been discovered on Cape Cod beaches. So cold that caretakers at the Calgary Zoo in Alberta, Canada once brought their group of king penguins indoors to protect them (since the birds, native to islands north of Antarctica, aren't accustomed to extreme cold). Even regions like Alabama and parts of the Deep South have faced subzero wind chills and single-digit temperatures.
Fortunately, this arctic chill isn't permanent: The temperatures will slowly rise again.
