Winter Storm Xylia, a Potentially Historic Blizzard in the Rockies and High Plains, Hits This Weekend

The Weather Channel

The storm has been named Winter Storm Xylia (pronounced ZEYE-lee-uh) by The Weather Channel.

A gyre of low pressure aloft will carve its way into the Southwest and take its time before it moves out early next week. Slow-moving upper lows like this one are notorious Rockies and High Plains snowstorm generators.

The spiraling low will tap deep moisture from the Gulf of Mexico and pump it up the slope of the High Plains into the Front Range of the Rockies, where air just cold enough to support snow will be in place.

This storm is also forecast to produce flooding rain and several days’ worth of severe thunderstorms in other parts of the Plains and Mississippi Valley.

Current Alerts

Winter storm warnings have been issued for portions of Colorado and Wyoming, including Cheyenne, Wyoming; Denver, Boulder and Fort Collins, Colorado. Travel could be impossible in this area.

Winter storm watches have also been issued for parts of southern Wyoming, the Nebraska Panhandle, northern Utah, and Colorado.

The National Weather Service in Cheyenne, Wyoming, called this a “potentially historic event taking shape” in their Wednesday afternoon forecast discussion and mentioned “blizzard conditions possible”.

The Timeline

Xylia is currently bringing showery weather to the Southwest.

Snow showers will continue in the Four Corners into Friday.

This will be a slow-moving system, meaning for some, once it starts, it will take a while to pass.

Some areas of light snow may spread into the Front Range and High Plains of southeast Wyoming and northern Colorado by Friday afternoon.

Here’s when snow may reach your area:

Winter Storm Xylia’s heaviest snow will shift into gear late Friday night through Saturday and Sunday before gradually tapering Sunday night and early Monday.

This is when the storm’s most serious and dangerous impacts are expected.

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How Much Snow and Potential Impacts

There is relatively high confidence that the Interstate 25 corridor from southeast Wyoming into northern Colorado and adjacent foothills will pick up 1 to 2 feet of snow.

This includes Colorado’s Front Range Urban Corridor of Denver, Fort Collins and Boulder and Wyoming’s capital city, Cheyenne.

This one-foot-plus snow potential also extends into at least the western Nebraska Panhandle, as well as the Black Hills of western South Dakota.

Peak snow totals in the foothills and mountains west of Cheyenne and Denver could reach 3 feet.

Snow may fall at the rate of several inches per hour at times Saturday and Sunday and could be accompanied by thunder and lightning.

(MORE: Here’s How Many Winter Storms Happen in Spring)

This is a dangerous storm ahead with potentially life-threatening impacts.

Roads – including stretches of Interstates 25, 70, 76 and 80 – in the High Plains and Front Range are likely to become impassable and may be closed this weekend.

You should avoid all travel in eastern Wyoming, western Nebraska and northeast Colorado from the foothills eastward from late Friday night through Sunday. If not, you run the risk of being stranded. Some road closures may linger into at least Monday, given the prolific snow totals forecast.

The combination of wet, heavy snow and strong winds may damage trees and trigger power outages. The weight of the snow may also lead to roof collapses in some areas.

The storm also poses a danger to livestock left out in the open.

Historic Snowstorm?

Spring snowstorms are the norm in the High Plains and Front Range of the Rockies each year.

In Cheyenne, Denver and other parts of the High Plains, March is the snowiest month of the year.

But this may not be just another spring snowstorm.

In Cheyenne, Wyoming, Xylia could be its heaviest snowstorm on record. The two-day and three-day snowstorm of record was from November 1979, when just over 25 inches of snow pummeled the city just before Thanksgiving.

Xylia could also be the heaviest snowstorm in Scottsbluff, Nebraska, since a mid-April 1927 storm dumped 25.8 inches of snow in three days in the western Nebraska town.

‼️ Whiteout conditions & hazardous travel will be a major impacts as early as Friday, especially Saturday into Sunday evening. ‼️

❄️We will continue to monitor the forecast & give lead time ahead of this significant event! #WYwx #NEwx pic.twitter.com/xfNvu0vyZe

— NWS Cheyenne (@NWSCheyenne) March 10, 2021

In Denver, the National Weather Service tweeted Wednesday that Xylia had a “low to medium potential” to approach the March 2003 historical snowstorm.

That March 17-19, 2003, snowstorm dumped 31.8 inches of snow on the Mile High City, its second heaviest snowstorm dating to 1881, according to the NWS.

According to Storm Data, this heavy, wet snow lead to roof collapses to homes and businesses. At least 258 structures were damaged in Denver.

The weight of the snow tore a gash into the tent roof of Denver International Airport, forcing an evacuation of part of the terminal.

The foothills and mountains west of Denver were buried by 50 to 87 inches of snow. Avalanches closed many foothills and mountain roads, including Interstate 70 in both directions for some time, stranding travelers. Thousands of residents in the foothills of Jefferson County, Colorado were trapped in their homes by snow-choked roads.

Up to 135,000 customers lost power during the storm, some for several days.

The 2003 storm was the costliest snowstorm on record in Colorado, with an estimated $93 million damage.

https://weather.com/storms/winter/news/2021-03-10-rockies-plains-major-snowstorm-xylia