CHICAGO (Nexstar) — An Arctic blast is beginning to make its way south through the U.S., bringing the coldest air of the season to most of the country, and the cold air might stick around for most of February.
The freezing air is due to chunks of the polar vortex breaking off and heading southward into the United States.
The freezing polar vortex is usually contained over the Arctic and North Pole by the prevailing jet stream winds. A “sudden stratospheric warming event,” which happens about six times a decade, according to NOAA, destabilized the polar vortex. During these events, the winds that normally flow from west to east around the pole weaken dramatically and even reverse direction.
That warming event is prompting the coldest air of the winter to break off from the vortex and trek southward across much of the United States, reaching as far south as Texas next week, according to KXAN.
Parts of Michigan are already facing storms and will see their first sub-zero temperatures in nearly two years – since the last polar vortex visited that area.
Wind chills in parts of North Dakota have a chance of reaching minus 50 degrees Friday night, with wind chills in parts of South Dakota not much better at minus 20 to minus 30.
The National Weather Service in Chicago has warned of dangerous wind chills in that area as well.
The worst of the cold will shift east with time, and may move to the Mid-Atlantic and Northeast by the second half of next week.
The one warm spot in the forecast? Tampa on Super Bowl Sunday will see highs in the low 70s and there is a 50% chance of rain in the morning and early afternoon.
