The United States could be headed for some extreme weather this winter. That’s the early prediction from Severe Weather Europe, a website that tracks weather patterns around the globe. Three factors ...

This winter, with record snow in New Orleans and drought and destructive wildfires in Southern California, has not been normal.

The polar vortex is area of fast-moving winds well above the Earth’s surface and the jet stream that circle the Arctic during the Northern Hemisphere’s coldest months.

These polar vortex stretches are happening more frequently as the world — and especially the Arctic — warms, a 2021 paper published in the journal Science, also co-authored by Cohen, demonstrated.

Winter, which is warming faster than any other season for much of the US, seems to be making a comeback for the first time in years; this January was the coldest in the Lower 48 since 1988.