It’s the "Bleak Midwinter" in the Northern Hemisphere – so, in case you’ve been living under a well-insulated rock, cold weather and snowfalls are hardly unexpected in many parts of the world. However,

A lobe of the Polar Vortex is going to swing through Ontario just north of Michigan. The upper-air forecast gives us an easy look at this strongest winter player.

It's a term you hear every couple of winters, when we get stuck in the coldest of cold patterns – polar vortex. But what exactly is it?

Thanks to the polar vortex, it feels like one, too. Why is it so cold? The Philadelphia region was hammered Monday by the season’s first big storm, with some areas in Delaware and the lower Jersey Shore collecting eight or more inches of snow.