“Short periods of heavy snow, strong winds and rapidly dropping temperatures could cause sudden power outages, momentary icing and icy roads,” the National Weather Service wrote. “Dangerous cold is expected even in areas unaffected by snow .”
Nearly 70 million people are under winter storm watches or warnings across the Midwest, the Great Lakes and the Appalachians, and Minnesota recently issued a blizzard warning.
Snow and strong winds could affect major airport hubs, including Chicago’s O’Hare International Airport and Detroit Metropolitan Wayne County Airport. The combination of snow and wind gusts in excess of 40 mph will result in blowing and drifting snow with near-zero visibility at times, especially in an area stretching from western Kansas and Nebraska north to Minnesota and east to western New York .
“Power outages are expected … Travel becomes very difficult or impossible,” the National Weather Service in Minneapolis wrote. “If you are stranded, this event may be life-threatening.”
Cities that can handle blizzard conditions between Thursday and Friday — at least for a short time — include Kansas City, Missouri, and St. Louis, Missouri. St. Louis, Des Moines, Minneapolis, Milwaukee, Chicago, Indianapolis, Detroit and Buffalo.
In some places around the Great Lakes, including Buffalo, wind gusts could reach 50 to 65 mph, causing severe tree damage and power outages amid dangerously low temperatures.
Areas that avoid snowfall eastward from the Rockies will not be able to avoid near-record low temperatures of 40 degrees or more below normal. Wind chill watches, advisories and warnings affecting about 90 million people extend from the Canadian border to Texas and as far east as Tennessee, with subfreezing temperatures likely to drop to the Gulf of Mexico. In some places, December temperatures will be the coldest in decades.
In the north-central US, actual temperatures are expected to be between minus 20 and minus 40 degrees, with wind chills likely approaching minus 60 degrees. The National Weather Service in Bismarck, North Dakota, called the cold “life-threatening.”
“Dangerously cold wind chills can cause frostbite on bare skin in as little as 5 minutes,” it reads.
The cold will hit the East Coast on Friday, arriving suddenly in the form of a lightning freeze that could cause temperatures to plunge by 25 degrees or more in just a few hours. After a morning of heavy rain and possibly brief snowfall, the lightning freeze could turn some roads into a dangerous layer of ice that could make driving on major roads like Interstates 95, 84 and 81 extremely dangerous.
In the Northeast, the same storm system — which can intensify quickly enough to qualify as a weather “bomb” — pushed seawater toward the coastline, causing coastal flooding.
An upper-altitude disturbance characterized by high-altitude cold air, low pressure and rotation will sneak into the Central Plains from British Columbia and Alberta on Wednesday and Thursday. It will explosively strengthen a surface area of low pressure across the Plains, transforming it into a powerful storm system sweeping across the Ohio Valley. By Friday night, it will be sailing into Quebec and Ontario on its way to Hudson Bay.
The storm will quickly intensify into a bomb cyclone, the strongest term for a mid-latitude weather system. Its pressure will drop from 1,003 millibars Thursday night near the Indiana-Ohio border to 968 millibars Friday night — the approximate pressure of a Category 2 or 3 hurricane in southern Quebec. A mid-latitude storm whose pressure drops by 24 millibars in a 24-hour period is considered a weather bomb—the storm’s pressure is expected to drop by 35 millibars over that time period. The lower the pressure, the stronger the storm.
As the low pressure system rotates counterclockwise, the system will draw a puff of mild air on its east side. That will see rainfall dominate much of the mid-Atlantic and Northeast. The exception is the Appalachian Mountains, specifically the Allegheny Mountains in western Maryland, western Virginia and eastern West Virginia, where the cold air entrenched in the mountains is hard to wash away.
The National Weather Service is warning of 4 to 7 inches of snow east of the Allegheny front, in addition to a quarter inch of freezing rain. This will happen in the first half of the month on Thursday. That’s just one storm ahead of Friday’s lightning freeze – not only in the mountains, but also in the coastal plains – including Washington and Baltimore.
A Major Plains and Great Lakes Snowstorm
Further west, though, the Plains, the upper Midwest, and even parts of the South Central, possibly as far south as Nashville, will see snow—and, for some, a lot of it. The jackpot, which could be a foot or more, looks to fall on Michigan’s Upper Peninsula, with the next biggest tailwinds being Lakes Erie and Ontario.
Even in areas with only a few inches of snow, travel is still expected to be very dangerous as high winds will limit visibility.
British stone. St. Louis, Kansas City, Omaha and the Twin Cities are all under winter storm warnings with the potential for 2 to 6 inches of snow — less in the south and more in the north. West Minneapolis, blizzard warning in effect; combination of 40-50 mph winds and moderate to heavy snow could see snowy conditions Thursday night through storm peak Friday, while windy and cold Wind chills below minus 30 degrees are possible.
Winter storm warnings are in effect for Chicago, Detroit and Indianapolis. And this is where confidence in snowfall levels dwindles. In the Windy City, the total might be anywhere from 3 to 6 inches, but going up a steep incline; as one floats toward Michigan, the buildup climbs quickly, with a foot or more likely to land on some part of the glove.
After the storm, cold air blowing from the west-northwest across Lakes Erie and Ontario may produce some lake effect snow, although this is not typical wind direction for extreme snowpack as it does not blow longitudinally toward the lakes. Instead, there could be a foot or so over the weekend, although meteorologists are still fine-tuning the details.
The Buffalo Weather Service wrote that “travel over the holiday weekend, including Friday, will at times be very difficult or impossible” through Monday.
Following the storm, a stream of air from Siberia will divert south into the United States for about 72 hours, affecting nearly everyone east of the Rocky Mountains. It will spread over the Canadian border first, blowing south as a cold front into the early hours of Wednesday that will drop temperatures by 40 degrees or more in less than six hours.
A bone-chilling chill will hit Denver Wednesday night, dropping temperatures from 40 degrees to zero in just a few hours. By Thursday morning, temperatures will be close to minus 10 degrees, with wind chills of around minus 30 degrees.
“Life-threatening cold set in late Wednesday,” Tweeted the Office of Weather Services serving Denver“We promise it’s not an exaggeration. It’s probably the coldest day in Denver in 32 years, so a lot of people haven’t experienced a cold snap like this.”
In the Dakotas, temperatures could drop to around minus 30 degrees on Friday night. In Bismarck, they have been below zero since Sunday and will remain there until Christmas. Wind chills of minus 40 degrees are possible. Breaking down in a vehicle without an emergency kit can quickly kill you.
The cold will pour south, reaching St. Louis. Louis Thursday. Highs will peak in the mid-30s with snow falling quickly to around minus 3 degrees overnight. No more than single digits on Friday.
In Oklahoma City, it won’t get above 11 or 12 degrees on Thursday. In the Texas Panhandle, temperatures could dip from near 50 degrees on Wednesday to the low teens by midnight. Locally, such fronts were called “blue northerners”.
The cold will roll all the way down the Gulf Coast by Thursday afternoon, turning the ocean into what appears to be a smoky lagoon. This will be due to “Arctic sea smoke”, or a distinctive fog that forms when cold air blows over warm waters.
Lightning Freeze in the Eastern United States
The cold will reach the East Coast on Friday, but it will come suddenly. That’s a hazard for those traveling on the interstate, especially between Washington, D.C., and Hartford, Connecticut.
Temperatures Friday morning will be in the 40s to close to the 50s, with rain likely as moisture spirals into the parent low pressure system in the Northwest. If a cold front sets in around midday, readings will plummet to 20 degrees, with temperatures potentially dropping 25 degrees or more within three hours. Meanwhile, very brief snowfall is possible.
Crews were unable to pre-treat the roads due to the rain, and any lingering moisture and puddles could quickly turn to ice. This can make the road very dangerous. Strong winds are likely to help dry roads before they freeze, but treacherous travel is risky.