CNN
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An intensifying winter storm will bring more than a foot of snow and possible blizzard conditions to the Midwest as the National Weather Service warns of “life-threatening” wind chills for millions.
The storm and cold snap will affect nearly every state and bring what the weather service calls a “once in a generation event” that will cripple travel on some of the busiest travel days of the year.
More than 90 million people are under winter weather warnings and more than 87 million people are under wind chill warnings. The alert spanned 37 states and stretched south to the Texas/Mexico border.
The cold will continue into the Christmas weekend, making the Plains and parts of the Midwest the coldest Christmas in about 40 years.
Wednesday: The storm will strengthen the Northern Plains during the day as heavy snow falls across much of the Rocky Mountains, Northern Plains and Midwest. In places like Minneapolis, Omaha and Rapid City, slick roads can cause travel headaches and airport delays.
The Twin Cities Office of Weather Services said the system will bring 5 to 9 inches of light snow to the area, with “the highest snowfall in the north and west of the Twin Cities.” While the region will see steady snowfall, strong winds won’t pick up until Thursday.
Denver will fall from a high of 47 on Wednesday to a low of -14 on Thursday morning. It will be the city’s coldest day in 32 years, according to the Bureau of Meteorology.
Thursday: Thursday will be the most difficult day for travel. The storm will hit the Midwest with heavy snow and strong winds. Not only is western Minnesota facing blizzard conditions, but deadly winds are possible on Thursday and Friday.
“Snowy conditions are expected during that time, making travel very difficult or impossible,” the weather service said. “This event could be life-threatening if you’re caught in a wind chill of -30C to -45C.”
Chicago could also face snowstorms with winds of up to 50 mph, with 2 to 4 inches of snow expected.
“Overall, concerns continued to increase regarding the rapid development of hazardous conditions Thursday afternoon, which could have a significant impact on the evening peak travel window,” the Chicago Weather Service warned.
In addition, strong winds could damage power lines in the Midwest, especially in areas where heavy snowfall last week has already weighed down tree branches. It will allow millions of people to find a way to keep warm as temperatures plummet to well below freezing.
On Thursday, snow could fall as far as Jackson, Tennessee, Mississippi, Memphis and Nashville, and even Birmingham, Alabama. Most southern cities are expected to see little to no snow, but Nashville could see about an inch of snow.
In anticipation of what will be a travel nightmare next week, United, American, Delta, Southwest and JetBlue have issued travel waivers to dozens of airports across the country from the South to the Northeast because nothing but snow Outside of covered roads, poor visibility can make air travel dangerous.
Friday: The storm is expected to turn into a “bomb cyclone” Thursday night through Friday. A bomb cyclone is a storm that intensifies rapidly and drops 24 millibars (a term used to measure atmospheric pressure) in 24 hours.
The storm is expected to reach the equivalent of a Category 3 hurricane when it reaches the Great Lakes, with the weather service describing the depression as a “once-in-a-lifetime” event.
“Snowfall totals may not tell the whole story under these conditions. Even a small amount of snow, combined with extremely strong wind gusts and plunging temperatures, can lead to poor visibility and slick spots on the roads. Sudden arrival increases danger,” Weather Service Explanation.
The storm will sweep through the Great Lakes on Friday and continue to bring heavy snow across much of the Midwest. Parts of Michigan could see more than a foot of snow through Friday, making travel at times impossible.
Heavy rain will also blanket much of I-95, adding to travel hassles and lengthy airport delays.
Even where the snow has ended, strong winds of 30 to 40 mph will still blow through much of the Midwest and into the Northeast.
New England will experience rapid snow and wind through Friday night and Saturday morning.
Where you can escape the snow, you cannot escape the cold. Areas from eastern Montana to the Dakotas will experience the coldest air starting Thursday morning. Temperatures in these locations will be 40 degrees below normal. A combination of low temperatures and windy conditions will keep the wind chill down to minus 50 degrees.
Temperatures in Rapid City will dip below minus 45 degrees on Thursday morning. Chicago’s wind chill will drop to minus 30 degrees by Friday morning.
“Dangerously cold wind chill can cause frostbite on bare skin in as little as 5 minutes,” the Bismarck Weather Service Office warned.
Even the south will be dangerously cold. Wind chills in Nashville and Atlanta will drop to minus 11 degrees Saturday morning, with temperatures dropping to minus 5 degrees in Birmingham.
Both Jackson and Birmingham will spend more than 80 hours in sub-zero temperatures from Friday to Monday. Houston could stay below freezing for 46 hours Thursday through Saturday.
The frigid temperatures will continue throughout the Christmas weekend before finally easing off next week.