A growing winter storm that could bring blizzard conditions and more than one foot of snow to the Midwest in the few days left before Christmas is expected to affect 37 states. Wind chills that are "life-threatening" will affect millions.
The National Weather Service is predicting a "once in a generation type event" that will cause travel disruptions on some of the busiest travel days of the year as a result of a significant winter storm and cold blast that will affect almost every state.
Winter weather alerts are in effect for more than 90 million people, and wind chill alerts are in effect for more than 87 million. The warnings cover 37 states, dipping just south of Mexico's border in Texas.
Christmas will be the coldest in about 40 years for some areas of the Plains and Midwest because of the prolonged cold weather that will persist through the holiday weekend.
Remaining Days to Christmas
Wednesday. As heavy snow blankets the majority of the Rockies, the Northern Plains, and the Midwest throughout the day, the storm will intensify over the Northern Plains. Travel difficulties and airport delays will result from slick roads through cities like Minneapolis, Omaha, and Rapid City.
The region will receive 5 to 9 inches of light, fluffy snow from this system, with the highest amounts occurring just north and west of the Twin Cities, according to the weather service office in Minneapolis.
Denver will experience its coldest day in 32 years on Thursday morning when temperatures drop to minus 14 from a high of 47 on Wednesday.
Thursday. The storm, which will hit the Midwest hard with strong winds and heavy snow, will make Thursday the most challenging day for travel. Along with blizzard conditions, Western Minnesota will experience potentially fatal wind chills on Thursday and Friday.
According to NWS, whiteout conditions are anticipated during that time, making travel extremely challenging or impossible. If someone were to become stranded with wind chills between 30 and 45 below zero, it could be life-threatening.
In addition, blizzard conditions with winds gusting up to 50 mph and 2 to 4 inches of snow could affect Chicago.
The rapid emergence of hazardous conditions on Thursday afternoon, which could have a significant impact on the evening peak travel window, has raised concerns, according to NWS in Chicago.
In the Midwest, particularly in areas where a lot of snow fell the previous week and is already putting strain on tree branches, strong winds may also down power lines.
On Thursday, snow is possible to fall as far south as Memphis, Tennessee; Jackson, Mississippi; and Nashville, Tennessee, as well as Birmingham, Alabama. Most southern cities are predicted to experience little to no accumulation; however, Nashville may experience an inch or so of snowfall.
United, Delta, American, Southwest, and Jet Blue have issued travel waivers for dozens of airports nationwide, from the South to the Northeast, anticipating a week of travel nightmares because, in addition to snow-covered roads, low visibility could make flying hazardous.
United has outlined several requirements for changing flight plans, and it also serves as a gentle reminder that change fees have been eliminated as of January 31, 2021.
Friday. On Thursday evening and into Friday, the storm is anticipated to intensify into a "bomb cyclone." When a storm intensifies quickly and loses 24 millibars in 24 hours, it is called a bomb cyclone.
The weather service has described the storm's strength as a "once in a generation" event, with the storm expected to reach the pressure corresponding to a Category 3 hurricane as it approaches the Great Lakes.
On Friday, the storm will pass over the Great Lakes and continue to dump a lot of snow across the Midwest. By Friday, parts of Michigan could receive more than a foot of snow, making travel challenging at times.
The I-95 corridor will also be heavily rained on, which will make traveling more difficult and cause protracted airport delays.
Strong winds will persist across a large portion of the Midwest and into the Northeast at 30 to 40 mph, even where snowfall has stopped.
New England will experience a brief snowfall and windy conditions Friday night into Saturday morning.
Read also: Winter Storm Watches Issued for Central US Due to Heavy Snow and Chill Winds
Life-Threatening Wind Chills
The National Weather Service defines dangerous wind chills as being -20F or lower, which is the temperature at which exposed skin can become frostbitten in less than 30 minutes.
Beginning on Thursday morning, the coldest air will be felt in parts of eastern Montana through the Dakotas. The temperatures will be 40 degrees below average for these locations. Wind chills could reach 50 degrees below zero due to the combination of cold temperatures and windy conditions.
On Thursday morning, Rapid City will feel like it is 45 below zero. Chicago's wind chill will reach its lowest point on Friday morning at 30 degrees below zero.
On Saturday morning, the wind chill in Birmingham will feel like minus 5, while it will be minus 11 in Nashville and Atlanta.
Between Friday and Monday, Jackson and Birmingham will both experience more than 80 hours below zero. Between Thursday and Saturday, Houston may experience 46 hours of below-freezing temperatures.
The cold weather will last through the holiday weekend before finally abating the following week, CNN reports.
Related article: Heavy Snow Could Unload in Central U.S. This Week; Slowed Travel Expected in Oklahoma, Dallas and Houston