What is a Polar Vortex?

Edward Stojakovic, Flickr // CC BY 2.0
Edward Stojakovic, Flickr // CC BY 2.0

If you’ve turned on the news or stepped outside lately, you're familiar with the record-breaking cold that is blanketing a lot of North America. According to The Washington Post, a mass of bone-chilling air over Canada—a polar vortex—split into three parts at the beginning of 2019, and one is making its way to the eastern U.S. Polar vortexes can push frigid air straight from the arctic tundra into more temperate regions. But just what is this weather phenomenon?

How does a polar vortex form?

Polar vortexes are basically arctic hurricanes or cyclones. NASA defines them as “a whirling and persistent large area of low pressure, found typically over both North and South poles.” A winter phenomenon, vortexes develop as the sun sets over the pole and temperatures cool, and occur in the middle and upper troposphere and the stratosphere (roughly, between six and 31 miles above the Earth’s surface).

Where will a polar vortex hit?

In the Northern Hemisphere, the vortexes move in a counterclockwise direction. Typically, they dip down over Canada, but according to NBC News, polar vortexes can move into the contiguous U.S. due to warm weather over Greenland or Alaska—which forces denser cold air south—or other weather patterns.

Polar vortexes aren't rare—in fact, arctic winds do sometimes dip down into the eastern U.S.—but sometimes the sheer size of the area affected is much greater than normal.

How cold is a polar vortex?

So cold that frozen sharks have been known to wash up on Cape Cod beaches. So cold that animal keepers at the Calgary Zoo in Alberta, Canada once decided to bring its group of king penguins indoors for warmth (the species lives on islands north of Antarctica and the birds aren't used to extreme cold.) Even parts of Alabama and other regions in the Deep South have seen single-digit temperatures and wind chills below zero.

But thankfully, this type of arctic freeze doesn't stick around forever: Temperatures will gradually warm up.

A Pile of Manure and a Heat Wave Combined to Cause Spain’s Worst Wildfire in 20 Years

Lumppini, iStock/Getty Images Plus
Lumppini, iStock/Getty Images Plus
A pile of manure in Spain ignited on June 27, sparking a wildfire that has torn through more than 10,000 acres of forest and other Catalonian landscapes, CNN reports. The manure combusted in part because of a scorching heat wave that has swept across Europe this week; temperatures in the affected region hit 104°F, and Germany, Poland, and the Czech Republic all reached record-breaking June temps. Catalan regional interior minister Miquel Buch reported that authorities believe the manure was improperly stored on a chicken farm in the village of La Torre de l’Espanyol, where it was exposed to the worst of the heat, according to NBC News. The wildfire—Spain’s most devastating in 20 years—is affecting the region just west of Tarragona, a port city that is best known for its Roman ruins, which is situated along the Balearic Sea about 60 miles southwest of Barcelona. [[{"fid":"315211","view_mode":"width-constrained-728","fields":{"format":"width-constrained-728","field_file_image_title_text[und][0][value]":false,"field_file_image_alt_text[und][0][value]":"Map of Catalonia, Spain","field_image_subhead[und][0][value]":"","field_image_subhead[und][0][format]":"unfiltered","field_caption[und][0][value]":"","field_caption[und][0][format]":"unfiltered","field_credits[und][0][value]":"PeterHermesFurian%2C%20iStock%2FGetty%20Images%20Plus","field_credits[und][0][format]":"unfiltered"},"type":"media","field_deltas":{"1":{"format":"width-constrained-728","field_file_image_title_text[und][0][value]":false,"field_file_image_alt_text[und][0][value]":"Map of Catalonia, Spain","field_image_subhead[und][0][value]":"","field_image_subhead[und][0][format]":"unfiltered","field_caption[und][0][value]":"","field_caption[und][0][format]":"unfiltered","field_credits[und][0][value]":"PeterHermesFurian%2C%20iStock%2FGetty%20Images%20Plus","field_credits[und][0][format]":"unfiltered"}},"link_text":false,"attributes":{"alt":"Map of Catalonia, Spain","height":728,"width":728,"class":"media-element file-width-constrained-728","data-delta":"1"}}]] The firefighting force includes about 350 firefighters, 12 fire engines, seven aircraft, two hydroplanes, and additional vehicles equipped with water tanks—all of which are techniques regularly used to fight massive blazes. Though high temperatures are expected to continue and the rough terrain itself is also a contributing factor in the rapid spread of the fire, the strong winds should soon abate; authorities have warned people to stay inside. Though more than 50 people have been evacuated from the area, no deaths have been reported thus far. While the spontaneous combustion of flammable materials like manure, hay, or compost is definitely possible, as evidenced by this situation, it’s not the most common way for wildfires to start. More common causes include lit cigarettes, unattended campfires, burning debris, and engine sparks. [h/t CNN]

Colorado Welcomed Summer With 2 Feet of Snow

Emmanuel Dunand/AFP/Getty Images
Emmanuel Dunand/AFP/Getty Images

While people in some parts of the country celebrated the first day of summer with barbecues and trips to the beach, residents of north and north-central Colorado had a snow day. Areas west of Denver—including Grand Lake, Aspen, and Steamboat Springs—experienced snow storms on summer solstice, with snowfall totaling nearly 2 feet at the highest elevations, CBS Denver reports.

Snow started falling in the Rocky Mountains the morning of Friday, June 21 and continued Sunday. Areas at ground level weren't cold enough to experience the unusual weather, but at elevations of 7000 feet and above, it looked like a winter wonderland. Steamboat Springs, a ski resort town in Colorado’s Yampa Valley, accumulated 20 inches of snow on the longest day of the year.

While Colorado mountain towns are used to seeing snow at odd times of year, the weekend's weather was still out of the ordinary. The average snowfall for Steamboat Springs in June is 0.1 inches. Prior to last Friday, it had been 91 years since a snowstorm hit the city in late June.

Snow has fallen in the Rockies later than average in six out of the past seven years. Though it feels like an extension of winter, the trend may actually be a product of the warming atmosphere. A warmer climate affects the jet stream, potentially pushing its course further south and leading to unusual weather patterns, such as unseasonable snowstorms in Colorado.

That means residents of some parts of the state will have to wait to have their summer hikes and picnics. The weather was serious enough to shut down one road in Rocky Mountain National Park.

[h/t CBS Denver]

SECTIONS

arrow
LIVE SMARTER