polar vortex
noun
plural polar vortices also polar vortexes
: a persistent rotating portion of the atmosphere above the polar region of a planet or moon
Mars, like Earth, is observed to have a polar vortex in its winter hemisphere, with a strong westerly flow …—Stephen Hughes et al.
New analysis suggests unique atmospheric chemistry explains why the polar vortex on Saturn's moon Titan isn't behaving as expected.—Brooks Hays
A nearly ubiquitous feature of planetary atmospheres in the solar system are rapidly rotating flows in polar regions, that are generally referred to as polar vortices.—Dann M. Mitchell et al.
especially
: a strong westerly flow of air above the Earth's North Pole that may become unstable and expand especially in the winter sending cold air southward with the jet stream
The sudden warming of the stratosphere is a subtle but impactful event because it's the very first key to weakening and unlocking the polar vortex, which can send pockets of frigid cold air south into the U.S. —Ken Mahan
The service said there are a few factors influencing the forecasted cold snap, including potential for a weakened polar vortex system, which could push Arctic air south from the North Pole and hit the country. —Janson McNair
Polar vortexes may dip down to … turn warm conditions quickly into major snow events with blizzard conditions. —Ricky Kemery
Cite this Entry
“Polar vortex.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/polar%20vortex. Accessed 14 Nov. 2026.
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