The first storm will bring rain and snow on September 14-15 and snowflakes could fall as low as 10,000-11,000ft. Then a second storm will likely bring colder temperatures and maybe enough moisture for snow in about one week, around Thursday, September 21. In between these systems, we'll see a mix of sunny skies and times of showers.
We started this week with a dusting of snowfall near and above treeline. The treeline is generally between 11,000-12,000 feet.
Below is a webcam snapshot from the Alpine Visitors Center at Rocky Mountain National Park taken on Monday morning.
Most or all of this early-season snowfall melts when the sun shines, so this is not the start of base building for the winter, but the snow is fun to see!
Looking ahead, there will be two chances for colder weather and higher-elevation snowfall.
Storm Sep 14-15
From Thursday morning, September 14 to Friday evening, September 15, a storm will rotate through Colorado and will produce rain and snow across all mountain ranges.
The coldest temperatures will be over the northern and north-eastern mountains near the divide where snowflakes could fall as low as nearly 10,000 feet. Around the central and southern mountains, the snow level may drop to around 11,000-12,000 feet.
During the daytime, all roads should just be wet, though, during the dark hours or early in the morning, some of the highest-elevation passes could see some snow/ice on the road.
Below are two snow forecasts for Thursday through Friday.
The European model is excited for snow! The geographic extent of the snow is likely overdone, but this is fun to see.
Below, it's hard to find the snow in this National Weather Service multi-model forecast. I think this forecast is relatively accurate as only the higher peaks will see snow, but the extent of the snowfall might be a little underdone.
The precipitation on Thursday and Friday will be significant as some models show 0.50 to 1.00 inches of liquid accumulation, and this could translate to more than a dusting at the higher elevations near and above treeline with some spots getting 2-6 inches of snowflakes.
We are still in the early season and the high sun angle of September should melt most of this snow, so again, this is likely not the start of a base for winter.
Storm Sep 21
The second storm of the next week should arrive around Thursday, September 21, plus or minus a day.
The average of 51 versions of the European model shows a clear signal toward colder-than-average temperatures around the 21st, indicated by the blue color on the map below.
Based on multiple forecast models, I have high confidence that we will see cooler air around September 21st, though I have low confidence about how much precipitation we will see during this cooler period, so it's too early to know if there could be a lower-elevation snowfall or if the cooler temperatures will be accompanied by mostly drier air.
Around the U.S. and Canada
Alan has the full scoop in the most recent US and Canada Daily Snow post. In short, there is snow coming to Alaska, around the west, and there will be a stormy period for the east with Hurricane Lee.
Around the World
Our worldwide Powder Finder shows that it continues to snow hard in South America (it just snowed about 3 feet in 8 hours!), flakes will fall in Australia and New Zealand, and the higher peaks of the Rockies here in the western US will see snow next week.
Access the Powder Finder here.
Below is a copy/paste from my previous post.
The central Pacific Ocean is much warmer than normal and this will influence weather patterns around the world. But here in Colorado, the impact of El Nino is not clear-cut.
Looking at past winter seasons with El Nino, we see that snowfall winds up being close to average.
However, there is one notable trend, which is that there is often above-average snowfall during the early months and late months of the season (October, November, March, April) and below-average snowfall during the middle months of the season (December, January, February).
For more details about El Nino's impact on snowfall here in Colorado and at certain mountains, tap the links below:
- Colorado winter forecast
- Aspen winter forecast
- Copper Mountain winter forecast
- Steamboat winter forecast
- Telluride/Silverton winter forecast
- Vail winter forecast
- Winter Park winter forecast
- Wolf Creek winter forecast
I'll post again in September and October when the weather warrants it, and then I will start daily coverage most likely in late October.
Thanks for reading!
- October 12 at the Westin Riverfront in Avon
- November 9 at the American Mountaineering Center in Golden
Steamboat, Granby, Beaver Creek, Vail, Ski Cooper, Copper, Breckenridge, Keystone, Loveland, Arapahoe Basin, Winter Park, Berthoud Pass, Eldora, Rocky Mountain National Park, Cameron Pass
Along the Divide
Loveland, Arapahoe Basin, Winter Park, Berthoud Pass
East of the Divide
Eldora, Echo, Rocky Mountain National Park, Cameron Pass
Aspen, Sunlight, Monarch, Crested Butte, Irwin, Powderhorn
Telluride, Silverton – north side of the southern mountains | Purgatory, Wolf Creek – south side of the southern mountains