The winter storm that has blanketed Colorado with brutally cold arctic air and snow continued Monday, ensnaring mountain traffic, canceling flights and closing schools.

The National Weather Service issued a Winter Storm Warning and a Wind Chill Warning for the central mountains, southern Colorado, the Front Range and the Eastern Plains Monday. Heavy snowfall was expected in the mountains. Wind speeds on the plains were expected to be above 50 mph, which could lead to temperatures of at least 20-degrees below zero. Both warnings were in effect until Tuesday.

“We’re seeing there’s still snow continuing (in) the mountains, foothills, and even portions of the plains right now,” said Caitlyn Mensch, a forecaster at the National Weather Service in Boulder. “We’re seeing that there’s very hazardous travel conditions right now, especially in the mountain passes. So, if you can avoid travel up there, it’d be definitely advised.”

On the Western Slope, heavy snow was expected to continue, though gradually lightening up by the end of the day. Though the end of falling snow didn't signal the end of winter hazards. The NWS posted to X, formerly Twitter, cautioning drivers to be wary of icy roads and increased avalanche risks.

Several highways were closed in the central mountains, including I-70, I-25 and numerous mountain passes, according to the Colorado Department of Transportation's COTrip website.

Lisa Schwantes, the regional communications manager for CDOT in southwest Colorado, said the storm was impacting travel in the high country from Southwest Colorado up the Western Slope and the I-70 corridor.

“What we are dealing with is just frigid, frigid temperatures, cold and high winds. And of course that just causes white out conditions blowing snow and low visibility, zero visibility,” Schwantes said.

The Martin Luther King Jr. Day weekend is one of the busiest traffic weekends in the mountains, as people travel to and from ski resorts. But with heavy snow affecting the roads, traffic in many areas was at a standstill.

“If you’re in your car and you’re at a standstill, stay in your vehicle. Turn it off and on periodically to keep the heat going a bit, but save your gas, [and hope] that these safety closures don’t last more than an hour or two,” said Schwantes.

The length of a closure depends on several factors, Schwantes said.

“It just depends on what Mother Nature is throwing our way. It depends on what type of slide-offs of other vehicles is occurring ahead of you and the equipment needed to turn those vehicles the right direction,” she said.

At Denver International Airport, nearly 350 flights were canceled on Monday, according to the flight tracking website FlightAware. Over 550 flights were delayed, as of Monday afternoon.

Several school districts and universities announced they'd cancel classes on Tuesday, due to the weather.