The Colorado Avalanche Information Center has announced that an avalanche warning is in effect for the southern San Juan Mountains through 8 a.m. Wednesday.
The warning followed a storm that dumped 5-10 inches of snow in the valleys and lower elevations of Southwest Colorado on Monday and up to 16 inches in the mountains. The National Weather Service forecast for New Year’s Day calls for continued snow across the southern mountains and valleys before snowfall scatters and becomes isolated on Tuesday night. A winter storm warning remains in effect until 5 p.m. Tuesday. Additional snow accumulations of 6 to 12 inches of snow were expected, along with 40 mph wind gusts.
The threat of avalanches will be elevated late Monday to “high” – level 4 out of 5 – and includes the southern San Juan, La Plata and Needle mountains as well as the Grenadier Range.
“Intense snowfall on Monday night will result in a widespread avalanche cycle,” the Avalanche Information Center said. “Very dangerous conditions will continue through the day Tuesday.”
Natural avalanches are likely to release and run long distances, the center said. An avalanche triggered in the new snow can break on deeper weak layers, creating a large and deadly avalanche.
Travelers were cautioned to avoid travel on or under steep slopes, especially those that face northwest through north to east, where Monday’s storm snow has been blown into thick slabs above weaker snow. Avalanches may be triggered from the bottoms of slopes, from adjacent slopes, or from a distance.
“Give slopes a wide berth and use extra caution around steep terrain features if they end in trees, cliffs, or gullies,” the avalanche center said.
On Dec. 22, the center reported the nation’s first avalanche death of the 2018-2019 season after a snowmobiler died in the Horse Creek area of the Wyoming Range at 9,150 feet in elevation.
Dennis Phillips, a meteorologist with the National Weather Service in Grand Junction, said the New Year’s storm was playing out as predicted, and the heaviest snow should fall overnight Monday evening into Tuesday.
Travel will be affected.
Commercial vehicles on Coal Bank, Molas, Red Mountain and Wolf Creek passes are required to have chains or alternative traction devices. Passenger vehicles are required to have snow or mud/snow tires, use chains/alternative traction devices or have a four-wheel/all-terrain vehicle.
Colorado Department of Transportation crews will begin avalanche mitigation work at 6 a.m. Wednesday at Wolf Creek on U.S. Highway 160, which received 2½ feet of snow. Traffic delays of up to an hour are expected, CDOT said. Eastbound traffic will be stopped at the Treasure Falls chain-up station at mile post 157, and westbound traffic will be stopped near the pass summit at mile post 166.
Tony Vicari, director of the Durango-La Plata County Airport, said morning flights were able to leave Monday, but delays because of snow are expected.
“It’ll slow down operations throughout the day into tomorrow,” he said. “But so far we’ve had nothing significant.”
The Durango Herald contributed to this article.