Polar vortex and the chaos causing our cold snap

Plus: the weather forecast where you are
A frosty morning in Kendal, Cumbria, on Sunday
A frosty morning in Kendal, Cumbria, on Sunday

After the recent wild weather, calm has been restored, but now with a raw air bringing frost and ice. Much of the blame for this change in the weather is on the polar vortex — powerful winds whirling around the Arctic at over 150mph.

News media often describe the polar vortex as a whirlpool of winds racing around as a jet stream. But the vortex is much higher than the jet stream, about 15 to 50km high in the stratosphere.

Yet the polar vortex can influence the jet stream; a strong polar vortex favours a strong jet stream, but a weak vortex tends to weaken the jet stream and make it buckle into a wavy pattern. In a typical British winter, the jet stream drives