A polar vortex collapse is set to strike in mid-March, bringing severe winter weather and major travel disruptions across the US and Canada. The intense cold could also reach the UK and Europe, raising concerns across the region.
This will be the second polar vortex collapse of 2025, following an earlier event that caused freezing conditions and transport chaos across North America.
What is polar vortex collapse?
A polar vortex collapse occurs when the strong, cold winds that normally circulate around the Arctic or Antarctic weaken and break apart, allowing frigid air to spill southward into lower latitudes.
This can lead to extreme winter weather, including severe cold waves, heavy snowfall, and icy conditions in regions that don’t usually experience such intense cold.
How does polar vortex collapse happen?
The polar vortex is a large area of low pressure and cold air over the Earth’s poles, usually kept in place by strong westerly winds. When the vortex weakens or is disrupted by sudden stratospheric warming (SSW) – rise in temperature by up to 50 degrees within 48 hours – the wind patterns change, breaking up the vortex.
Therefore, instead of staying trapped near the poles, the frigid air moves southward, bringing freezing temperatures to places like North America, Europe and even Asia.
How, where and when will polar vortex collapse impact?
AccuWeather’s Lead Meteorologist Paul Pastelok told The Independent that when the polar vortex is disrupted – whether stretched, displaced, or split – it can, but does not always, impact this polar jet stream.
Regions across the US witnessed widespread snow, storms, and below-freezing temperatures in February. If the upcoming vortex disruption weakens the jet stream, icy air from the polar regions could push into North America or Eurasia.
“We are predicting a displacement of the polar vortex on the Europe and eastern Canada side of the polar,” Pastelok said. “The timing is uncertain for North America but could see a change in the pattern for late March into early April,” he added.
