Meteorologists blame a stretched polar vortex, moisture, lack of sea ice for dangerous winter blast

A major stratospheric warming high above the Arctic is disrupting the polar vortex. And it is poised to push Arctic air into North America and Europe. Forecast models are signaling a rare, high-altitude disturbance that could significantly shift winter weather for millions over the next few weeks. A sudden stratospheric warming is unfolding, with upper-air temperatures surging by tens of degrees within days. This rapid heating is weakening the polar vortex—the fast high-altitude winds that usual

How does the polar vortex lead to Arctic outbreaks?

Polar Vortex: How the Jet Stream and Climate Change Bring on Cold Snaps - Inside Climate News