What is a polar vortex? The experts explain. | Bot To News


Chicagoans are no strangers to cold weather, but some of the terminology used to describe frigid conditions can be confusing.

That’s why experts from the Chicago office of the National Weather Service, Meteorologist Brett Borchardt and Lead Forecaster Matt Friedlein, answered some common questions about extreme cold to provide some clarity. Their responses are listed below.

“As in recent years, our start to winter has been relatively mild with mild stretches and limited snow,” Borchardt said. “The reality of living in Chicago is that snow and cold will come eventually whether we like it or not!”

Borchardt and Friedlein: “A polar vortex is a large low-pressure system that is accompanied by cold air from the Arctic that usually originates near the North Pole. Since the systems are so large, they typically take a long time to move across the country, leading to an extended period of cold weather. As a result, polar vortices are often accompanied by periods of snow, windy winds, and generally unpleasant weather.”

Borchardt and Friedlein:While the term polar vortex gained notoriety after the freezing cold outbreaks of January 2014 and late January 2019, most cold outbreaks are associated with polar vortices. It is quite normal for polar vortices to emerge toward the southern United States during the winter months, especially behind winter storms. The combination of cold polar air and fresh snow cover is what typically leads to our coldest days and nights.”

Borchardt and Friedlein:We normally experience polar vortices every winter, although most are not as cold as the ones we most remember. It seems like we have to deal with a bad polar vortex once every five to ten years, though that’s an anecdotal measure. Polar vortices, at least the ones that are the nastiest, generally occur within the late December to early February time frame.”

January 30 and 31, 2019

Chicago recorded its coldest temperatures in 34 years, minus 23 degrees on January 30, 2019, and minus 21 degrees on January 31, 2019 at O’Hare International Airport, the city’s official site of record. Both are among the 10 coldest in the city.

The lowest temperature ever recorded in Illinois was observed on January 31, 2019, when Mount Carroll (west of Chicago in the northwestern pocket of the state) registered -38 degrees.

January 5-7, 2014

Chicago earned the nickname “Chiberia” with temperatures plummeting to minus 16 degrees, which was 30 to 40 degrees below normal. Winter 2013-14 was the third coldest and snowiest winter on record here.





Source link