DENVER – Colorado’s mountains are on track to get their first heavy snow of the season Thursday through Friday, though Denver’s chances of breaking its snow-free streak seem to be decreasing by the hour.
Winter storm warnings and winter weather advisories remain in effect for most of the higher-elevation mountains through Friday afternoon, with general accumulations forecast to be around 8 to 20 inches in areas under winter storm warnings, and with some locally higher totals possible near Rabbit Ears Pass and in the San Juan Mountains.
West Jackson and west Grand counties are forecast to get 15-30 inches in the storm; the Rocky Mountain National Park and Medicine Bow Range areas can expect 10-20 inches; the eastern Sawatch and San Juan Mountains could see 20 to 30 inches; and the mountains further west could see 1 to 2 feet.
“Snowfall amounts up to 2 feet seem likely above 8500 to 9000 feet and wouldn’t be surprised to see some of the higher elevation snotels receive close to 3 feet of snow from this system. The valleys, however, remain a bit uncertain,” NWS Grand Junction forecasters wrote Thursday morning.
Winter weather advisories are in effect for Summit County, the Mosquito Range, and Indian Peaks until 5 p.m. Friday, with 4 to 10 inches of snow expected.
A winter storm watch is in effect for the I-70 corridor near Glenwood Springs and Parachute, where about 3 to 6 inches of snow are expected.
Winds could gust up to 50 miles per hour across much of the high country during the storm as well, the National Weather Service said.
Snow had already developed by late Thursday morning across most of western Colorado, and moved eastward through the day Thursday, which is when the heaviest snow is expected to fall, according to forecasters.
More snow had started to develop across the mountains as of 5 p.m. Thursday, and the storm was expected to strengthen through the evening. The National Weather Service said travel would not be recommended in the mountains Thursday night into Friday morning.
By 5 p.m., more than 11 inches had already fallen near Rabbit Ears Pass, and the heaviest snowfall totals extended along a line from there to the east toward Rocky Mountain National Park. Several areas in Summit County had also received 3 inches of snow by 5 p.m.
Snow is accumulating in those mountains! Here's an estimate of how much snow has fallen so far, but plenty more to come. Heaviest totals so far roughly along/north of a line from Rabbit Ears Pass to @RockyNPS. #COwx pic.twitter.com/dMyxxPseK5— NWS Boulder (@NWSBoulder) December 9, 2021
The Colorado Avalanche Information Center issued avalanche warnings for the Steamboat/Flat Tops, Aspen, Gunnison, North San Juan and South San Juan zones from 4 p.m. Thursday until 11:59 p.m. Friday.
“Heavy snow and strong winds will result in numerous natural avalanches on Thursday night,” the CAIC said. “Very dangerous avalanche conditions continue into Friday with human-triggered avalanches very likely.”
While the mountains need the snow badly amid ski season and to boost snowpack levels for the start of the water year amid a historic western drought, folks in the Denver area and out on the plains have been hoping for snow to not only allay what has been one of the driest back halves of the year ever, but to also break the snow-free streak.
Unfortunately, forecast snow totals for Denver and the plains continue to drop from the meager 1-2 inches that were forecast for this storm earlier this week, and there is now a question if Denver will even see the one-tenth of an inch that is needed to be considered measurable.
The National Weather Service said Thursday the cold front should arrive in the Denver area around 3 a.m. Friday but that snow might not develop – if it does at all – until around 7 a.m.
“[The] best chance for the I-25 corridor will be right behind the front Friday morning into midday,” NWS Boulder forecasters wrote Thursday morning, saying drier downslope air will move in Friday afternoon.
But the forecasters did not sound thrilled about the latest models bringing any substantial snowfall to the metro area.
“It’s hard to envision much snowfall occurring in that narrow window Friday morning given so many things against it, most importantly dry low-level air in place, then reinforced during the afternoon, and essentially no upslope flow east of the foothills,” they said.
“It’s quite possible many areas along the Front Range get no snow at all,” the forecasters continued. “High res models really don’t like snowfall chances for the I-25 corridor.”
All that said, forecasters wrote they still believe up to an inch could fall in the metro area, and possibly an inch or two on the northeast plains.
There will also be northwesterly winds on the plains gusting 25-40 miles per hour on Friday. In the mountains, snowfall rates are expected to stay moderate Friday morning before tapering off around midday.
Thursday would mark the 232nd consecutive day without snow in Denver if it doesn't fall by the end of the day, good for second on the all-time record books. The longest snow-free streak in Denver came in 1887, when the city went 235 consecutive days without snow. This year has already by far set the record for the latest first snowfall in Denver, and November was one of the warmest and driest on record for the city.
Statewide snowpack had jumped to 52% of median as of Thursday morning – up from 49% on Wednesday, but still among the lowest yet seen at this point in a season since 1991.
But all basins in Colorado were below 70% of median ahead of the bulk of the storm, including at 28% of median in the Upper Rio Grande Basin, 35% in the Arkansas Basin, and 31% in the San Miguel, Dolores, Animas and San Juan Basin.
You can stay posted on the latest as this storm moves through Colorado the next two days on our website and on the free Denver7+ streaming app, where you can watch live weather updates and live radar conditions 24 hours a day on your TV.