Winter storm disrupts U.S. holiday travel: Midwest, Northeast face snow, wind threats

Arctic air blasted the Plains Sunday, as forecasters warned an "intense cyclone" system would threaten parts of the Midwest and Northeastern U.S. with heavy snow and blizzard conditions this week, while New England faces freezing rain.The big picture: The National Weather Service said other potential hazards for these areas over the next 48 hours include "widespread blustery winds to locally damaging winds," as a "potent winter storm" producing frigid temperatures sweeps across from the upper Midwest to the Great Lakes Sunday into Monday.Nearly 10 million people were under winter storm warnings, almost 3 million were under blizzard warnings and over 38 million were affected by winter weather advisories overnight.Holiday season travel was severely disrupted, with an estimated near-10,000 flights into or out of the U.S.delayed late Sunday, as blizzard and winter storm warnings were in effect across Iowa, Michigan, Minnesota and Wisconsin — where officials were urging people to avoid travel if possible. Screenshot: Minnesota DOT District 7/XThreat level: Minnesota was among the worst-affected states, and Gov. Tim Walz "authorized the National Guard to support emergency winter storm operations as we work to alleviate dangerous conditions on the roads," per a statement posted to the governor's social media channels.The NWS' Twin Cities office warned on X parts of Minnesota faced "DANGEROUS, POTENTIALLY LIFE-THREATENING" travel conditions into early Monday from threats including strong winds and heavy snow.Sections of Interstate 35 closed in Minn. and Iowa Sunday afternoon "due to numerous crashes from the winter storm," NWS Twin Cities noted.The Great Lakes could see snowfall amounts that well exceed a foot, "particularly along the south shore of Lake Superior where 2 feet of snow is possible together with whiteout conditions at the height of the storm," the NWS said in a forecast discussion.Zoom in: In Michigan, the NWS' Marquette office said in a forecast discussion the heavy snowfall would cause "very difficult to impossible travel conditions, with blizzard conditions resulting in near-zero visibility at times."In Iowa, the NWS' Des Moines office said in its forecast discussion that regardless of snowfall amounts, any additional snow with the strong winds was likely to produce "blowing snow," making travel hazardous into Monday morning.In New York, where Gov. Kathy Hochul declared a state of emergency Friday due to a post-Christmas storm, the NWS Buffalo office said on X strong to damaging winds of up to 70 mph were likely.High wind warnings were in effect Sunday downwind of Lake Erie as well as for Jefferson County northeast of Lake Ontario, per and NWS Buffalo forecast discussion.These winds, "combined with the lake effect snow will create blowing and drifting snow, with very poor visibility expected within the lake effect snow bands by Monday evening," NWS Buffalo said.Meanwhile, thunderstorms were set to impact areas "from the Arklatex to the Midwest" later Sunday, followed by the Ohio/Tennessee valleys and the Deep South into Monday morning, the NWS said in a forecast discussion."A couple of tornadoes and damaging wind gusts are possible with some of these storms in the Ohio Valley this afternoon owing to the unusually warm and moist pre-frontal airmass in place," per the NWS.Driving the news: "A low pressure system is rapidly developing over the Mid-Mississippi Valley along an Arctic front as the incoming frigid air from Canada mingles with the anomalous warm airmass that has settled across the Central/Southern U.S. for many days," the weather agency said.What's next: The NWS said a mix of snow, sleet and freezing rain was set to impact northern New England by Monday morning, before warmer air changes the wintry mix to rain later in the day.Southeastern New Mexico and Southwest Texas face threats from "blowing, accumulating snow falls near the tail end of the Arctic front" on Monday, according to the weather agency. Screenshot: NWS Weather Prediction Center/XEditor's note: This is a breaking news story. Please check back for updates.