An unusual and powerful late season winter storm is hitting Wyoming this Monday morning, with the National Weather Service Office in Cheyenne issuing one Snow storm warning and multiple Winter Storm Warnings across much of the state beginning at 8:40 a.m. MDT, May 18, 2026.
The system has caught motorists and commuters off guard at a time of year when trees have already fallen across the region – making the heavy, wet snow particularly destructive.
The NWS Cheyenne office clearly stated in its Blizzard Warning bulletin: “Travel should be limited to emergencies. If you must travel, make sure you have a winter survival kit. If you are stranded, stay with your vehicle.”
Snowstorms are currently occurring Interstate 80 in the foothills of the North Snowy Rangeincluding the communities of Arlington and Elk Mountain, where wind gusts reached 50 miles per hour Visibility may drop to less than a quarter mile by falling and blowing snow.
A multi-zone warning spanning Wyoming’s mountain corridors
The reach of the storm is large. Across the Snowy Range and North Laramie Range – including Centennial and Albany – the NWS predicts 10 to 20 inches of total snow accumulationwith gusts of 20 to 40 mph and significant blowing and drifting above 8,500 feet. The South Laramie Range, which spans the critical areas I-80 summit between Cheyenne and LaramieThere is a warning for 7 to 14 inches and wind gusts up to 25 mph.
In Central Carbon County, including Rawlins5 to 10 inches are expected with wind gusts up to 30 miles per hour and visibility could possibly fall below a quarter mile. The Sierra Madre Range faces 8 to 16 inches concentrated on the eastern slopes, with 50 mph wind gusts that could cause tree damage. Casper Berg 6 to 12 inches are warned, and the NWS specifically notes that heavy snow can break tree branches as many trees have already leafed out – an unusual hazard unique to late spring storms. The city of Kasper himself is expected to receive 3 to 6 inches, with up to 8 inches possible between Hiland and the city’s south side.
The storm is spreading into Colorado
The system does not end at the Wyoming border. NWS Denver has issued a winter storm warning for Rocky Mountain National Park and the Medicine Bow Range in Colorado, valid until 9 p.m. MDT, with expected snow accumulations of 8 to 18 inches on east-facing slopes – threatening travel on mountain passes and impacting the Monday evening commute. Traffic conditions in Colorado and Wyoming can be checked on wyoroad.info or by calling 511.
The event is a vivid reminder of what meteorologists know well: in the central Rocky Mountain corridor, winter doesn’t keep to the calendar. May storms of this magnitude, while uncommon at lower elevations, are not unprecedented in the highlands. What makes the current system remarkable is its size: simultaneous blizzards and winter storms in six different mountain areas in Wyoming, all active on the same Monday morning.
