Nearly 70 million people are under winter alerts nationwide, with a powerful weather system expected to bring a potent mix of snow, ice and blizzard conditions, accompanied by winds gusting up to 50 mph, according to CNN.

The winter storm, which has already caused snowy and icy conditions in the Central Plains, will create treacherous travel conditions and potential power outages across a vast region stretching from Missouri to the mid-Atlantic.

“For some, this could be the heaviest snowfall in over a decade,” NOAA’s Weather Prediction Center warned.

Major effects, including “considerable disruptions to daily life … dangerous or impossible driving conditions and widespread closures,” are expected from this storm through Sunday in parts of the Central US, according to the Winter Storm Severity Index.

What to expect when

Of the 70 million people under winter alerts, nearly 4 million are under blizzard warnings across much of eastern Kansas and western Missouri, with a dangerous combination of snow, ice and freezing rain ongoing across Kansas, Missouri, southern Illinois and Indiana and western Kentucky. In addition, thundersnow and thundersleet are being observed.

Throughout the day, the storm will spread east into the Ohio River Valley, then reach the Mid-Atlantic late Sunday night into much of Monday.

• Kansas City, Missouri: Blizzard warning until 4 a.m. ET Monday, peaking Sunday morning through Sunday afternoon. Heavy snowfall expected between 6 to 14 inches with a glaze of ice and winds gusting to 45 mph.
• St. Louis, Missouri: Winter storm warning until 7 a.m. ET Monday, peaking Sunday morning through Sunday evening. Heavy mixed precipitation, icy at first turning to snow. Total snow and sleet accumulations between 4 and 12 inches and ice accumulations up to four-tenths of an inch possible.
• Indianapolis, Indiana: Winter storm warning through 7 p.m. ET Monday, peaking 1 p.m. Sunday – 7 a.m. ET Monday. Heavy mixed precipitation with total snow accumulations between 6 and 9 inches along with a glaze of ice.
• Louisville, Kentucky: Winter storm warning through 7 p.m. ET Monday peaking noon Sunday – 7 a.m. ET Monday, with a secondary snow burst Monday afternoon and evening. Heavy mixed precipitation with total snow accumulations between 6 and 10 inches along with ice accumulations up to three-fourths of an inch.
• Cincinnati, Ohio: Winter storm warning through 11 p.m. ET Monday peaking noon Sunday – 7 a.m. ET Monday, with a secondary snow burst Monday afternoon and evening. Heavy mixed precipitation with total snow accumulations between 5 and 10 inches along with ice accumulations up to .1 inch.
• Charleston, West Virginia: Winter storm warning through 1 a.m. ET Tuesday peaking 1 p.m. Sunday – 1 p.m. Monday ET, with a secondary snow burst Monday afternoon and evening. Heavy mixed precipitation with total snow accumulations between 4 and 7 inches along with ice accumulations between 1/2 and 1 inch.
• Washington DC: Winter storm warning 10 p.m. Sunday through 1 a.m. ET Tuesday, peaking 1 a.m. – 10 p.m Monday. ET. Snow mixed with sleet with total snow accumulations between 5 to 9 inches, with some suburban areas potentially getting up to a foot. A trace of ice accumulation.
• Philadelphia, Pennsylvania: Winter weather advisory 1 a.m. to 10 p.m. ET Monday, peaking between 6 a.m. – 6 p.m. ET. Snow accumulations between 2 to 4 inches.

Ice could cause hazardous conditions

Meanwhile, an ice storm warning remains in effect early Sunday for areas of southern Illinois, western Kentucky, and southeast Missouri. Travel of any kind in those areas is “strongly discouraged,” as the bridges and overpasses are likely to “become slick and hazardous,” according to the Weather Service.

The greatest risk of dangerous ice will set up just south of the snowiest areas. Significant icing is possible from Kansas and Missouri through the central Appalachians and potentially parts of Maryland and Delaware.

The National Weather Service said “significant icing” is expected.

“Total snow and sleet accumulations up to two inches and ice accumulations between one quarter and three quarters of an inch,” The National Weather Service said. “Persons should delay all travel if possible. If travel is absolutely necessary, drive with extreme caution and be prepared for sudden changes in visibility.”

The weather service in Topeka, Kansas, warned against traveling in the icy conditions.

“If you are thinking about hitting the road today, think again. Snow plows are getting stuck. Emergency vehicles are getting stuck. If you get stuck, it may be over 24 hours until someone can get to you,” NWS Topeka said on X. “Temperatures will fall below zero tonight. Do not risk it.”

Ahead of the storm, the governors of Kentucky, Virginia, West Virginia, Arkansas and Missouri declared states of emergency, while Maryland’s governor declared a state of preparedness.

“This winter storm will likely cause significant disruption and dangerous conditions on our roads and could cause significant power outages – just 24 hours before it gets dangerously cold,” Kentucky Gov. Andy Beshear said, according to a release from his office.

Beshear posted on X Sunday that all state office buildings will be closed Monday “due to inclement weather.”

Virginia Gov. Glenn Youngkin advised those with post holiday travel plans to consider leaving on Saturday instead of Sunday, given the projected size of the storm.

“I’m encouraging all Virginians, visitors, and travelers to stay alert, monitor the weather forecast, and prepare now for any potential impacts,” Youngkin said Friday.

Maryland Gov. Wes Moore’s office said in a Saturday news release the state is preparing for the storm, which will “likely affect roads and transportation centers and could cause significant snow accumulation in some parts of the state.”

Ice amounts of 0.25 inches or more are possible, especially in parts of southern Missouri, southern Illinois, southern Indiana and almost all of Kentucky.

Any amount of ice is dangerous; just a thin layer – a light glaze to just over 0.10 inches – can turn paved surfaces into skating rinks, causing people to slip and vehicles to slide out of control.

Power outages could be widespread and long-lasting if significant icing occurs and power restoration crews can’t navigate treacherous roads. The situation could be dangerous or potentially deadly for those without access to heat in the extreme cold to come.