A foot of snow in mid-March? A big storm is in the weather forecast this week.

Colorado this week could see its biggest snowstorm of the season with over a foot possible in the Denver metro area, forecasters said.

Snow began in Utah late Tuesday, before spreading south and east into Arizona, southern Wyoming and Colorado through the day on Wednesday, AccuWeather said.

"Widespread snow amounts of 6-12 inches are expected as the second half of the week progresses," said AccuWeather meteorologist Renee Duff.

How much snow will fall in Denver?

Weather.com meteorologist Chris Dolce said, "as for Denver, the heaviest totals will be in the foothills west of downtown and in the Palmer Divide south of the city, but the metro area has the potential to see 6 to 12 inches of snowfall."

The National Weather Service has issued a winter storm warning for the Denver area, which goes into effect Wednesday at noon and lasts until Friday morning. Due to the predicted snow-covered roads, "travel could be very difficult to impossible," the weather service said. A Wednesday map from the weather service says the region could see 12-18 inches of snow.

"If you must travel, keep an extra flashlight, food, and water in your vehicle in case of an emergency," the weather service advised.

In addition, "the snow from this storm is expected to be wet, heavy and clingy, which may result in power outages and down trees, especially in areas where a foot or more snow accumulates," Duff warned.

The snowstorm might also affect the major hub of Denver International Airport, as cancellations and delays could occur on both Wednesday and Thursday.

Due to the expected winter weather, Denver is opening up severe weather shelters and warming centers from Wednesday to Saturday, KDVR-TV reported. Also as of midday Wednesday, no decision had been reached by the Denver Public Schools about school closures for Thursday.

March snow not unusual in Denver

Dolce said that March is one of the snowiest months of the year in the Rockies.

Thursday is also the three-year anniversary of Denver’s last official double-digit snowstorm, according to a 9NEWS Weather report. On that date in 2021, 19.9 inches of snow fell in Denver, the weather service said, which was the city's snowiest March day on record.

This article originally appeared on USA TODAY: Denver, Colorado snow forecast says over a foot possible