Winter Weather Advisory Brings Up to 15 Inches of Snow and 55 mph Gusts Across the Rockies
A sweeping winter weather advisory warns of heavy snow, high winds and slick roads from Wyoming to Colorado today.
Mountain‑wide Snowfall and Wind Threats
Whoa! The National Weather Service has issued a winter weather advisory that blankets the South Laramie Range, the North Snowy Range foothills, Summit County, the northern Bighorn Mountains and the southeastern Bighorns.
Snow totals vary with elevation. The highest peaks could see up to 15 inches of snow by Monday night, while lower slopes are looking at 2‑4 inches in two rounds on I‑80’s summit between Cheyenne and Laramie.
Wind gusts are forecast to hit 55 mph on the I‑80 summit and in the southeastern Bighorns, with gusts of 40 mph on the North Snowy Range foothills and 45 mph in the northern Bighorns.
Specific Advisory Details
I‑80 Summit (Cheyenne to Laramie): Advisory runs 10 a.m. ET Monday to 1 a.m. ET Tuesday. Expect 2‑4 inches of snow in two bursts and gusts up to 55 mph, reducing visibility during the evening commute.
North Snowy Range Foothills (Arlington, Elk Mountain): Active 7 a.m.‑7 p.m. ET Monday, with 2‑4 inches of wet snow and gusts to 40 mph; bridges and overpasses may become slick.
Summit County, CO (Mosquito Range, Indian Peaks, Eisenhower Tunnel, Berthoud Pass, Winter Park, Breckenridge): From 7 a.m. ET Monday to 2 a.m. ET Tuesday, 3‑7 inches of snow and slippery roads are expected.
Northern Bighorn Mountains (MT/WY): Advisory until 10 p.m. ET Monday, up to 10 inches of snow and gusts to 45 mph, with the heaviest snow early Monday.
Southeastern Bighorns (above 9,000 ft): From 3 a.m.‑7 p.m. ET Monday, 6‑10 inches of snow, and the highest elevations near Cloud Peak could receive 10‑15 inches with gusts up to 55 mph. Granite Pass may see 5‑8 inches; Powder River Pass up to 2 inches.
Blow‑Over Risks on I‑80
Wyoming’s Department of Transportation continues to post closures for light, high‑profile vehicles when gusts reach dangerous levels. Since 2023, weight‑specific blow‑over warnings appear on I‑80, letting drivers of trailers and commercial trucks see if their load is at risk. Where those signs are absent, the warning reads “Extreme Blow Over Risk.”
Colorado Traction Requirements on I‑70
Drivers traveling through the Eisenhower Tunnel must comply with Colorado’s traction law, which applies on I‑70 between Dotsero and Morrison from September 1 through May 31. Vehicles need tires with at least 3/16 inch tread and one of the following: four‑wheel or all‑wheel drive, M+S‑marked tires, winter tires bearing the mountain‑and‑snowflake symbol, or manufacturer‑rated all‑weather tires. Vehicles lacking these must use chains or an approved alternative traction device.
Violations carry a standard citation of $100 plus a surcharge; if the vehicle blocks one or more lanes, the fine rises to $500 plus a surcharge.
Travel Implications
Roads, especially bridges, overpasses, and high‑elevation passes, are expected to turn slick. Visibility may drop below a quarter mile in several areas, making both Monday morning and evening commutes hazardous.
Motorists should stay alert to posted restrictions and the state’s 511 tools for real‑time updates.
