What is a polar vortex collapse? The weather phenomenon that's causing winter chaos in the US
Severe weather impacts the U.S. as March begins, with blizzards in the Upper Midwest and Great Lakes, and thunderstorms in Florida and the Mid-Atlantic. The National Weather Service warns a polar vortex collapse could extend harsh winter conditions into April.
The first days of March brought more severe weather across the United States, with a powerful low-pressure system causing blizzard conditions for parts of the Upper Midwest and Great Lakes.
This storm is expected to last through Wednesday night, with strong winds, heavy snow, and dangerously low temperatures. Meanwhile, Florida and the Mid-Atlantic region are facing continued thunderstorms as a cold front moves in, bringing a mix of stormy weather and potential risks for tornadoes.
What's the weather like for some areas in the US?
More blizzards and sub-zero temperatures are on the horizon. Today's forecast predicts a moderate risk of tornadoes, damaging winds, and lightning during the night and early hours of Thursday, with a low risk of large hail.
The rest of the country isn't faring much better. A massive winter storm is sweeping through the central U.S., bringing heavy winds, rain, snow, and freezing temperatures.
The destruction in Mississippi is clear, with the storm claiming two lives and damaging numerous properties. Irving, Texas was hit by a tornado with winds reaching 110 mph, causing significant damage.
Now, the National Weather Service is concerned that another phenomenon could extend the winter weather into April.
Forecasters are warning that another polar vortex collapse, similar to the one seen last month, could be on the way, bringing more Arctic air and "life-threatening" cold temperatures for the coming weeks.
What is a polar vortex collapse?
The National Oceanic and Atmospheric Administration (NOAA) describes the polar vortex as a vast area of low pressure and cold air currents that swirl around both poles of the Earth. It is most prominent during the winter months.
A polar vortex forms when the layer of the atmosphere between 10 and 50 kilometers above the Earth's surface experiences a rapid temperature rise of up to 50 degrees, typically within two days (known as sudden stratospheric warming or SSW).
This causes freezing Arctic air to move south, triggering snowstorms and plunging temperatures.
The key concern is whether the jet stream will split. AccuWeather’s Lead Meteorologist Paul Pastelok explained to The Independent: “We are predicting a displacement of the polar vortex over Europe and eastern Canada. When the Polar Vortex is disturbed — whether stretched, displaced, or split — it can, but not always, influence the polar jet stream. The timing for North America is uncertain, but we might see a shift in patterns from late March into early April.”