Science is Fun Fridays!

 

The polar vortex is a large area of low pressure and cold air which surrounds the North Pole.  It's a known pattern that usually goes unnoticed by those in lower latitudes, but every now and then the air pressure and winds shift.

Current temperature map.

Typically a large difference in the air drives the polar jet stream, but the Arctic is warming faster than other areas of the planet, which makes the difference less distinct.  This in turn causes the jet stream to meander around the planet more, causing the cold air to wobble, "and, like a toupee that goes askew, it can slip south off of the Arctic..."

Scientists are still investigating the connection between the polar vortex and sea ice, but believe it may be dampening the effect of climate change.  As worldwide climate warms, this dip of colder than usual air can keep average temperatures from warming as much as other places on Earth.

UCAR