Cortez and Durango could see at least a dusting of snow by Thursday morning and favored peaks in the San Juan Mountains could see up to 30 inches total by Friday morning from Southwest Colorado’s first significant winter storm of the season.
As of 2 p.m. Wednesday, only 3 inches had been reported on Red Mountain Pass, 3½ inches on Molas Pass and 5 inches on Coal Bank Pass, but most of the snow was expected to come in a second wave of the storm.
That second wave should move into the region around midnight Wednesday.
“It’s kind of a two-way system,” said Erin Walter, a meteorologist with the National Weather Service in Grand Junction. “The first wave came through Tuesday night and Wednesday morning, the second band will come through starting about midnight Wednesday.
“From midnight to 6 a.m. Thursday, we should see the highest levels of snowfall over the San Juans.”
The National Weather Service has issued a winter storm warning until 5 a.m. Friday for elevations higher than 8,500 feet in the San Juan Mountains. The winter storm warning also includes the towns of Telluride, Silverton, Ouray, Rico, and Lake City.
The weather service expects heavy, wet snow with most mountain accumulations between 8 inches and 12 inches, but with favored peaks getting hit with between 20 inches and 30 inches.
Travel is expected to be difficult or impossible over high mountain passes, and motorists should expect hazardous winter-driving conditions with poor visibility.
Colorado Department of Transportation didn’t have chain laws in effect on San Juan Mountain passes as of 4 p.m. Wednesday, but a news release said motorists should expect chain laws in effect when the peak of the snow-producing part of the storm is over Southwest Colorado, around midnight Wednesday to 6 a.m. Thursday.
The coldest part of the storm is expected to be Thursday night and Friday night, with lows in Cortez expected to dip to 19 Thursday night and 14 degrees Friday night. In Durango, the low Thursday is expected to be 22 and 16 Friday night.
Walter expected most of the moisture from the storm to be out of the Rocky Mountains by early Friday, and she expected most of Friday to be clear.
Another snow-producing storm could move into Southwest Colorado on Monday, but that storm is expected to favor north and central Colorado, and may not dip down to Durango and Cortez.
“The northern San Juans will see the most of it,” Walter said.
Snow would be welcome.
So far, Southwest Colorado’s snowpack is below the 30-year average for the season, according to the U.S. Natural Resources Conservation Service SNOTEL data.
As of Wednesday, snowpack in the Animas, Dolores, San Juan and San Miguel river basins was at just 16% of historic averages.
Since Sept. 1, a weather station at the Durango-La Plata County Airport has recorded 1.6 inches of precipitation – down more than 2.6 inches from historic averages.
The U.S. Drought Monitor has Southwest Colorado listed in a “severe drought.”