“Polar Vortex” sounds cool. It’s like “cyclone bomb” or “firenado”. This appears to be the kind of phenomenon that would be responsible for the record blast of cold, snow and wintry conditions that hit the Gulf Coast this week. The polar vortex is real, but it may not be responsible for the extreme cold that has buffeted normally warmer parts of the country.
Unusual winter storms and freezing temperatures have hit much of the United States, from Texas to Florida. Snowfall and cold weather caused flight cancellations and school, business and road closures. The National Weather Service has released its first ever blizzard warning for some areas around Lake Charles, Louisiana on January 21. Houston reportedly received snowfall up to 6 inches.
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NOAA’s Goes-East satellite captured a view of the historic winter storm in the southern United States on January 21.
The NWS office in Mobile, Alabama, issued a official snowfall measurement of 5.4 inches Tuesday afternoon, breaking the single-day record of 5 inches set in 1881. Snow was still falling and reached 7.5 inches for the day. THE Description of the NWS Social Media Team this total as “crazy”. Pensacola, Florida, experienced similar snowfall. It’s natural to look north, to the cold Arctic, to understand why the Gulf Coast plunged a polar bear into such frigid weather.
What is the polar vortex?
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The polar vortex can follow the jet stream and push cold air toward the United States under certain conditions.
As its name suggests, the polar vortex is associated with the north and south poles of our planet. It is an area of low pressure and cold air at each pole.
“Meteorologists examine the polar vortex by observing conditions tens of thousands of feet in the atmosphere; however, when we feel extremely cold air coming from Arctic regions to the Earth’s surface, it is sometimes associated with the polar vortex.” » said the NWS in an explanation.
The polar vortex may be linked to extreme cold spells in the United States, but the conditions must be right. The polar vortex can expand and push south with the jet stream – a narrow current of air that flows high in the atmosphere from west to east. Notably, a polar vortex hit the United States in 2019, triggering a volley of Star Wars Hoth jokes about the cold.
Did the polar vortex cause the cold?
The Arctic blast that sent shivers down the spines of Gulf Coast residents this week wasn’t necessarily an example of the polar vortex onslaught.
Amy Butler and Laura Ciasto of the National Oceanic and Atmospheric Administration blog about polar vortices on NOAA’s Climate.gov site. The scientists examined the polar vortex last week before the Arctic explosion. At the time, Butler and Ciasto spotted a potential stretching of the polar vortex. But there was another factor at play.
“Additionally, a strong ridge of high pressure formed simultaneously near Alaska, which may also help force the jet stream to dive south over the continental United States and carry with it cold Arctic air, independent of the polar vortex,” Butler said and Ciasto wrote.
A NOAA Video showed what the crest looked like:
The cold Arctic air that hovered over Alaska plunged south.
“I think the ridge over Alaska plays a bigger role in the cold air outbreak,” Ciasto told CNET. “The stratospheric polar vortex is not as extensive as it was last week, so the connection we highlighted in our last article is less relevant now.”
While the Gulf Coast caught cold, Alaska experienced an area of high pressure and milder temperatures, according to NWS public affairs specialist and meteorologist Erica Grow Cei.
“This in turn displaces the arctic air that is normally over our northernmost state at this time of year, and the arctic air moves downstream – to the southeast – to the continental United States,” Grow Cei told CNET.
The polar vortex can be a powerful source of winter weather, but it’s not the only cause of intense cold and snow in regions better known for their warmth and sunshine. The Gulf Coast states are still digging out of the snowdrifts, but at least warmer temperatures are expected heading into the weekend.
