Weather Academy: What is the polar vortex?

MONROE, La. (KNOE) - We’re talking about the polar vortex this week on the Weather Academy. Now we hear the words polar vortex a lot in the news, or even as we discuss our forecasts, especially in the wintertime, the polar vortex is happening all year round.

The polar vortex is an area of low pressure that has parked itself up on the North Pole and has air moving in a counterclockwise direction. Now we also have a polar jet stream or these strong upper-level winds that are usually camped out along the United States and Canadian border that’s helping to keep all the cold air off towards the north. When the polar vortex is kept to the north, the United States sees warm air throughout much of the year. This is a stable polar vortex. And usually, this is what we see in the summertime. During the summer, the polar vortex is weaker, and the polar jet stream is much stronger. But as we head towards the winter, we start to see our polar jet stream become a lot weaker and begins to wobble a bit. This will allow for cold air to surge towards the South. We then see a disrupted polar vortex. We also have warm air rushing north. And that’s when we start to see these troughs and ridges of winds across the United States.

When we see a stable polar vortex, warm conditions prevail, much like what we’ve been seeing the last couple of weeks here in December, and our polar jet stream stays well off towards the north. But if we start to see that become disrupted and the jet streams sink south, the arctic blast of cold air will be making its way into the region and even stretch as low as down into Texas and Louisiana for dropping temperatures across much of the South.

February 2021 is an excellent example of when we saw the polar vortex caused drastic impacts here in Texas, Louisiana, and across much of the South. That’s when we saw the 2021 ice storm that happened in February, temperatures dropped dramatically. We sat below freezing for extended periods, and strong winds out of the north caused our wind chills or feels like temperature to be even below freezing.

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