Meteorologists with the National Weather Service (NWS) issued a winter storm warning for three states this week as winter-like conditions could impact travel.

The warning was in effect for parts of Colorado, Utah and Montana. The winter storm was expected to bring heavy snow and strong winds to mountainous areas of western states.

In Colorado, the warning was in effect from Thursday evening until 9 p.m. local time Friday for the Uinta Mountains, including the towns of Manila and Dutch John. In Montana, the warning was in effect until midday Friday for the Gallatin and Madison County Mountains and the Centennial Mountains, including Big Sky, Targhee Pass, Raynolds Pass and West Yellowstone.

A separate Montana warning was in effect for Cooke County and the Absaroka/Beartooth Mountains until 3 p.m. local time Friday. In Utah, the warning was in effect for the Central and Southern Mountains, the Wasatch Mountains south of Interstate 80 and the western Uinta Mountains until Friday night or Saturday afternoon, depending on location.

“The roads are likely to become slippery and dangerous. Travel could become very difficult, if not impossible,” the Colorado warning reads. “Individuals should postpone all travel if possible.”

If travel is “absolutely necessary,” the Colorado warning urges motorists to “drive with extreme caution.”

“Leave plenty of space between you and the motorist in front of you and allow extra time to reach your destination,” the warning says. “Avoid sudden braking or acceleration and be particularly careful on slopes or when turning. Make sure your car is winterized and in good working condition.”

David Church, NWS science and operations officer, said Newsweek that wet fall storm systems like this are typical of high terrain near Salt Lake City this time of year, but warned that there will be “fairly significant snow accumulation.”

“Many seasonal routes are still open, and so people may still be heading into the backcountry for things like hiking, or it may be hunting season,” Church said. “It’s been warm and mild so far, so it’s a pretty dramatic change.”

Temperatures in the area were 10 to 15 degrees above normal, but winter brings temperatures below freezing.

All warnings advised people to carry an extra flashlight as well as food and water in their vehicle if they need to travel.

Up to 14 inches of snow was expected in Colorado, up to 22 inches was expected in Utah and up to 18 inches was expected in Montana.

“Winter driving conditions are expected on all mountain routes, including the higher passes along I-15 and I-70,” reads one of the Utah warnings.

“Some vehicles may require tire chains when driving over mountain passes,” said another.

In addition to the winter storm warning, there were winter weather warnings for parts of Montana, Oregon, Arizona, Utah, Wyoming and Nevada.