An Arctic outbreak featuring punishing cold weather is beginning across much of the U.S. at the same time that Europe prepares for plunging temperatures. Why it matters: About three weeks of cold east of the Rocky Mountains — potentially accompanied by major winter storms — will boost natural gas prices,

The vortex is essentially an area of low pressure in the upper layers of the atmosphere over the polar region. This vortex consists of powerful westerly winds in the stratosphere, about 10 to 30 miles about the North Pole, according to Climate.gov.