Colorado Weather Forecast #158: Dec. 26, 2021 - Jan. 3, 2022

Active pattern continues, several waves of snow through Jan. 1, then a lull.

This forecast is no longer valid. Please return to our list of forecast articles to find more recent posts.

Updated Sun Dec 26, 2021 2:00pm MST | Published Sun Dec 26, 2021

By Thomas Horner

7-Day Snow Planner (Through Dec. 31)

Northern Mountains

Park Range and N Front Range: Steamboat, Buffalo Pass, Rabbit Ears Pass, Bluebird, RMNP, IPW, Cameron Pass

6am New Snow

2-11"

Mon

2-11"

Tue

T-3"

Wed

T-4"

Thu

T-8"

Fri

1-10"

Sat

T-3"

Sun

6am Powder Potential

45%

Mon

35%

Tue

5%

Wed

9%

Thu

21%

Fri

41%

Sat

6%

Sun

I-70 Corridor

Front Range, Gore Range, etc.: Winter Park, Berthoud Pass, Jones Pass, Loveland, A-Basin, Keystone, Breck, Copper, Vail Pass, Vail, Beaver Creek

6am New Snow

1-9"

Mon

2-8"

Tue

T-4"

Wed

T-3"

Thu

T-5"

Fri

1-8"

Sat

T-3"

Sun

6am Powder Potential

31%

Mon

32%

Tue

8%

Wed

10%

Thu

13%

Fri

35%

Sat

9%

Sun

Central Mountains

Elk Mountains, Sawatch Range, Grand Mesa, West Elks: Aspen Resorts, Crested Butte, Powderhorn, Sunlight, Kebler Pass, Independence Pass, Cottonwood Pass, Monarch

6am New Snow

1-11"

Mon

2-13"

Tue

1-7"

Wed

T-5"

Thu

1-10"

Fri

2-12"

Sat

T-3"

Sun

6am Powder Potential

58%

Mon

66%

Tue

21%

Wed

13%

Thu

25%

Fri

56%

Sat

8%

Sun

Southern Mountains

San Juans: Telluride, Red Mountain Pass, Silverton, Coal Bank Pass, Purgatory, Wolf Creek

6am New Snow

2-15"

Mon

4-21"

Tue

3-13"

Wed

1-8"

Thu

1-13"

Fri

4-16"

Sat

1-6"

Sun

6am Powder Potential

47%

Mon

69%

Tue

50%

Wed

21%

Thu

38%

Fri

69%

Sat

13%

Sun

Denver Metro

Denver and surrounding suburbs: Lakewood, Westminster, Aurora, Highlands Ranch

6am New Snow

0-T

Mon

0-T

Tue

0-T

Wed

0"

Thu

0"

Fri

T-2"

Sat

T-1"

Sun

6am Snow Accum. Chance

11%

Mon

40%

Tue

45%

Wed

0%

Thu

7%

Fri

72%

Sat

67%

Sun

Summary

  • The previous wave almost singlehandedly brought Colorado back to median snowpack, with much more to come.
  • Heavy snow, snow squalls, strong winds today, powder day tomorrow for some areas.
  • Next wave: Dec. 27th - 28th. Snow totals could be a couple feet in areas.
  • Another wave Dec. 30th - Jan. 1. Powder day likely Jan. 1 at most resorts.
  • Still very little snow forecasted for Denver and the Front Range.
  • Lull from Jan. 2 - 5, pattern breaks down after then but will likely bring a good shot of snow to Colorado when it does.
  • Temperatures continue to cool as the main trough sags south. Snow will be fluffier and snow levels will be lower in elevation.

Retrospective

The first wave of snow of our active pattern cleared out yesterday, leaving some huge totals in the morning. Additional snow fell during the day yesterday, though not a whole lot of it.

By Dec. 25 5am:

  • Crested Butte S.A.: 41”
  • Wolf Creek: 33”
  • Aspen Highlands: 28”
  • Copper Mountain: 22”
  • Buffalo Pass: 20”+
  • Cameron Pass: 18”

We also saw on Silverton’s Instagram page that they were talking about totals in excess of 40” on the upper mountain.

Our forecast for this wave was conservative and we ended up with zero low busts and several high busts. OpenSnow’s less conservative forecast for the Aspen and Summit County areas helped them clinch the top spot for this storm, just narrowly edging us out! Both us and OpenSnow significantly outperformed the models, many of which were only half correct at best – human forecasters still have a place!

Forecaster / Model Rankings

Name Verification Score Bias
OpenSnow 71% 26% None
Thomas Horner (Highpoint Weather) 68% 21% Dry
NWS NDFD 53% 15% Dry
ECMWF (Euro) 50% 23% Dry
CAIC WRF 50% 20% None
NBM Prob. 50/90 50% 8% Dry
NBM Deterministic 46% 11% Dry
NAM 12km 31% -14% Dry
GFS 28% -5% Dry
NBM Prob. 25/75 6% -19% Dry

Our app had an 80% verification rate, but with much higher ranges than any other service, so we’re not sure if that was skillful enough to include in this ranking.

You can find the overall scores for this season, in addition to each storm’s verification here.

Snowpack

The large dose of heavy snow has added an overwhelming strain to the snowpack and created some weak interfaces. The CAIC has issued an avalanche warning across the state, including a special avalanche advisory for the Grand Mesa zone.

(via CAIC)
(via CAIC)

This dense snow has done wonders for our water deficit this season. Like we said – we weren’t giving up hope for the season, as many years have started out about as poorly and ended up above average. It just takes a few strong discrete storms, or a couple weeks of a more active pattern, to make a huge difference.

Sure enough, we’re already back to about median and we’ll likely be above-average by the start of 2022.

(via NRCS)
(via NRCS)

Current Conditions: Storm Dec. 26th

An approaching shortwave is introducing another shot of lift over Colorado which is tapping into some latent moisture. A strong jet maximum is directly overhead, which is organizing snow into bands that come complete with near zero visibility and intense winds.

The HRRR model’s simulated radar product has some very spicy pockets of heavy snow across Colorado this afternoon:

(via WeatherBell)
(via WeatherBell)

…with strong gusts of 90mph+.

(via WeatherBell)
(via WeatherBell)

The National Weather Service has been issuing Snow Squall Warnings.

(via Radarscope)
(via Radarscope)

You definitely don’t want to get caught driving in one of those bands.

Here’s a couple looks at potential snow totals through tomorrow morning.

(via CAIC)
(via CAIC)

Overall, additional powder is fairly likely in the southern San Juans, at the Aspen Resorts, at Crested Butte, and in the Vail area by tomorrow morning. Chances are there for parts of the western San Juans and Park range as well, and it’s likely parts of Summit County, Grand County, and the northern Front Range will get in on the action.

Banding means things will be hit-or-miss – some areas may not get nearly as much snow as their neighbors. Overall, looking at probabilities of snow, there may be more misses than hits, but we’ll see.

As has been the case, very little snow will make it east of the Divide.

Next Wave: Dec. 27th to 28th

There’s a bit of a lull in the action tonight before another wave of snow gets going from the morning of the 27th and into the morning of the 28th.

In this animation, you can see the first wave clearing Colorado, and then two waves rotating around the main trough into the 30th:

(via WeatherBell)
(via WeatherBell)

That second wave is what we’re talking about here – and overall, this is what we meant by a favorable, consistent pattern! That trough has been stuck over the western United States, and we get snow every time a little disturbance makes its way into flow aloft, which is almost every day.

Temperatures are also dropping as the trough descends further south, so this snow is not as dense and wet as the first wave.

Flow will again be predominantly southwesterly, but switch to more westerly and even a bit northwesterly on the morning of the 28th as the shortwave axis passes overhead. This still means the San Juans, Elk Mountains (Aspen and Crested Butte), Grand Mesa, Vail/Beaver Creek, and parts of the Park Range are favored, with Summit County and other areas likely getting significantly less snow…and very little snow east of the Divide (the I-25 corridor and foothills).

As has been the case, the jet will be overhead and some jet-induced banding will mix things up a bit, bringing extra snow to the Summit County area and letting a few bands of snow jump the Divide and bring a little bit of snow to the Front Range.

Here’s a reasonable upper end for potential totals from the 27th to the 28th:

Snow Forecast

Yes…powder everywhere. Our forecast for Dec. 27 5am to Dec. 29th 5am is something like this:

  • Wolf Creek: 20-40”
  • Purgatory: 15-30”
  • Telluride: 9-18”
  • Red Mountain Pass, Silverton: 12-24”
  • Crested Butte: 13-26”
  • Aspen Resorts: 10-20”
  • Vail, Beaver Creek: 8-16”
  • Breck, Copper: 7-14”
  • A-Basin, Keystone, Loveland: 6-12”
  • Winter Park, Berthoud Pass: 5-10”
  • Cameron Pass: 5-10”
  • RMNP: 3-9”
  • Steamboat: 7-14”
  • Eldora: 2-6”
  • Denver: 0-1”

That comes on top of today’s snow, of course.

We’ll put this into our official tool at some point, when we have time.

Next Wave: Dec. 30 - Jan. 1

The wave after looks a little more prolonged and a little moister, but we don’t have full certainty over that so the Blend’s guidance doesn’t look as good as the previous wave yet.

Snowfall ticks back up late the night of the 30th and well into the January 1st, wrapping up by the morning of the 2nd. Here are some perhaps middling expectations for the storm:

There’s too much uncertainty for details, but we think the morning of January 1st will be a powder day for most resorts. The Front Range also has slightly better snow chances with this setup, though still not great (seeing some support for up to 2-3” of snow in Denver though).

Lull: Jan. 2 - Jan. 5, then Pattern Change

There looks to be a lull from about January 2nd to January 5th. The pattern looks to finally break down after that – which will likely involve that main trough moving east and delivering one last parting shot of heavy snow to Colorado (possibly with northwest flow?) around the 6th of January. This could potentially deliver some snow to the Front Range, too.

How do blended totals look from now through the 6th? Pretty good, one would say, especially considering this model has a dry bias:

Thanks for reading, and hope you’re enjoying the snow!

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