Colorado Weather Discussion #150: Dec. 6 - Dec. 12, 2021

Updated snow accumulation forecasts for the Monday-Tuesday storm.

This forecast is no longer valid.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

Updated Sun Dec 5, 2021 11:00pm MST | Published Sun Dec 5, 2021

By Thomas Horner

7-Day Snow Planner (Through Dec. 13)

228

Days since the last measurable snowfall in Denver (At the official weather station / 2nd longest streak since record keeping began)

85%

Chance of accumulating snow in Denver by Dec. 13th (At the official weather station)

Northern Mountains

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

6am New Snow

2-7"

Tue

T-2"

Wed

T-3"

Thu

4-12"

Fri

2-5"

Sat

0"

Sun

0"

Mon

6am Powder Potential

25%

Tue

0%

Wed

5%

Thu

55%

Fri

20%

Sat

0%

Sun

0%

Mon

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

1-5"

Tue

0-1"

Wed

0-1"

Thu

1-6"

Fri

2-5"

Sat

0-T

Sun

0"

Mon

6am Powder Potential

15%

Tue

0%

Wed

0%

Thu

25%

Fri

20%

Sat

0%

Sun

0%

Mon

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

1-5"

Tue

T-2"

Wed

T-2"

Thu

4-10"

Fri

2-5"

Sat

0"

Sun

0"

Mon

6am Powder Potential

15%

Tue

0%

Wed

5%

Thu

60%

Fri

30%

Sat

0%

Sun

0%

Mon

Southern Mountains

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

6am New Snow

T-5"

Tue

T-2"

Wed

T-2"

Thu

5-12"

Fri

2-6"

Sat

0-T

Sun

0"

Mon

6am Powder Potential

15%

Tue

5%

Wed

5%

Thu

70%

Fri

35%

Sat

0%

Sun

0%

Mon

Denver Metro

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

6am New Snow

0"

Tue

0-T

Wed

0"

Thu

0-1"

Fri

T-2"

Sat

0"

Sun

0"

Mon

6am Snow Accum. Chance

5%

Tue

5%

Wed

0%

Thu

40%

Fri

70%

Sat

5%

Sun

0%

Mon

Summary

This is a supplemental discussion for our current valid forecast, please consult that article for any other details about the future weather forecast.

Not a lot of time tonight to actually get the full text and images associated with a nice detailed update, sorry about that. We have pored extensively through the data though to adjust our forecast.

  • A cold front associated with a shortwave has moved through the Front Range today, cooling temperatures down quickly behind it.
  • Several new fires in Colorado.
  • Monday to Wednesday storm is looking weaker (less energy).
  • Storm near the end of the week is still on track – nice totals in most of the mountains. Not too much snow for the Front Range, but still likely to be the first “official” snow of the year for Denver.

Forecast Discussion: Storm Monday to Wednesday

Snow Forecast Comparison and Verification Chart

Last updated Wednesday December 8, 2021 12pm.

Forecast Start: Monday December 6, 2021 5am

Forecast End: Wednesday December 8, 2021 5am

* = No reliable observations, verification uses SNODAS estimates which may be incorrect.
"Score" accounts for the spread/range of an accurate forecast. Lower spread = higher score. For instance, if 4" falls at a certain location, the forecast for 2-7" gets less points than the forecast for 3-5". Points are deducted for very inaccurate forecasts.

Thomas Horner Weather Forecaster @ Highpoint Weather

Issued Sun Dec. 5 11pm
✔️ Verified
84%
33/39
Score
31%
62/195
🎯 Spread
3.2
average
💥 High
3
7%
❌ Low
3
7%

Note: (Fri Dec. 3 11pm) Going for tighter ranges this time around.

Central Colorado
13/45pts (28%) ✔️9/9 (100%) 💥0/9 (0%) 0/9 (0%)

Aspen Highlands: 2-5" Forecast Actual2" ✔️

1pts
2" Dec 7 5am (Official)
0" Dec 8 5am (Official)

Aspen Mountain: 2-5" Forecast Actual2" ✔️

1pts
2" Dec 7 5am (Official)
0" Dec 8 5am (Official)

Aspen Snowmass: 2-6" Forecast Actual3" ✔️

1pts
2" Dec 7 5am (Official)
1" Dec 8 5am (Official)

Buttermilk: 1-4" Forecast Actual3" ✔️

2pts
2" Dec 7 5am (Official)
1" Dec 8 5am (Official)

Cottonwood Pass*: 1-3" Forecast Actual1" ✔️

2pts
1" Dec 7 5am (Estimated)
0" Dec 8 5am (Estimated)

Crested Butte: 1-5" Forecast Actual2" ✔️

1pts
2" Dec 7 5am (Official)
0" Dec 8 5am (Official)

Independence Pass*: 1-4" Forecast Actual2" ✔️

2pts
2" Dec 7 5am (Estimated)
0" Dec 8 5am (Estimated)

Kebler Pass*: 3-7" Forecast Actual4" ✔️

2pts
3" Dec 7 5am (Estimated)
1" Dec 8 5am (Estimated)

Monarch: 2-6" Forecast Actual2" ✔️

1pts
2" Dec 7 5am (Official)
0" Dec 8 5am (Official)

Front Range
11/25pts (44%) ✔️5/5 (100%) 💥0/5 (0%) 0/5 (0%)

Cameron Pass: 1-5" Forecast Actual3" ✔️

1pts
2" Dec 9am (SNODAS)
1" Dec 8 5am (SNODAS)

East Portal*: 0-3" Forecast Actual1" ✔️

2pts
0" Dec 7 5am (Estimated)
1" Dec 8 5am (Estimated)

Eldora: 0-2" Forecast Actual0" ✔️

3pts
0" Dec 7 5am (Official)
0" Dec 8 5am (Official)

Hidden Valley*: 0-3" Forecast Actual2" ✔️

2pts
1" Dec 7 5am (Estimated)
1" Dec 8 5am (Official)

St. Mary's Glacier*: 0-2" Forecast Actual1" ✔️

3pts
0" Dec 7 5am (Estimated)
1" Dec 8 5am (Official)

I-70 East
12/35pts (34%) ✔️7/7 (100%) 💥0/7 (0%) 0/7 (0%)

A-Basin: 1-4" Forecast Actual1" ✔️

2pts
1" Dec 7 5am (Official)
0" Dec 8 5am (Official)

Berthoud Pass: 1-5" Forecast Actual2" ✔️

1pts
2" Dec 7 9am (SNODAS)
0" Dec 8 5am (SNODAS)

Echo Mountain*: 0-1" Forecast Actual1" ✔️

4pts
0" Dec 7 5am (Estimated)
1" Dec 8 5am (Estimated)

Jones Pass: 1-5" Forecast Actual1" ✔️

1pts
1" Dec 7 8am (SNOTEL)
0" Dec 8 5am (SNOTEL)

Keystone: 1-3" Forecast Actual1" ✔️

2pts
1" Dec 7 5am (Official)
0" Dec 8 5am (Official)

Loveland S.A.: 1-5" Forecast Actual1" ✔️

1pts
1" Dec 7 5am (Official)
0" Dec 8 5am (Official)

Winter Park: 1-5" Forecast Actual2" ✔️

1pts
2" Dec 7 5am (Official)
0" Dec 8 5am (Official)

I-70 West
11/35pts (31%) ✔️7/7 (100%) 💥0/7 (0%) 0/7 (0%)

Beaver Creek: 2-6" Forecast Actual2" ✔️

1pts
2" Dec 7 5am (Official)
0" Dec 8 5am (Official)

Breckenridge S.A.: 1-4" Forecast Actual4" ✔️

2pts
4" Dec 7 5am (Official)
0" Dec 8 5am (Official)

Copper Mountain: 1-4" Forecast Actual4" ✔️

2pts
4" Dec 7 5am (Official)
0" Dec 8 5am (Official)

Powderhorn: 1-4" Forecast Actual2" ✔️

2pts
2" Dec 7 5am (Official)
0" Dec 8 5am (Official)

Ski Cooper*: 1-4" Forecast Actual2" ✔️

2pts
2" Dec 7 5am (Estimated)
0" Dec 8 5am (Estimated)

Sunlight*: 2-5" Forecast Actual2" ✔️

1pts
2" Dec 7 5am (Estimated)
0" Dec 8 5am (Estimated)

Vail Pass*: 1-5" Forecast Actual N/A

Vail S.A.: 2-6" Forecast Actual4" ✔️

1pts
4" Dec 7 5am (Official)
0" Dec 8 5am (Official)

Park Range / WY
0/20pts (0%) ✔️0/4 (0%) 💥1/4 (25%) 3/4 (75%)

Bluebird*: 2-6" Forecast Actual N/A

Buffalo Pass: 5-10" Forecast Actual3" ❌️

2" Dec 7 5am (SNOTEL)
1" Dec 8 5am (SNOTEL)
Note: SNOTEL recorded 0.5" of SWE change -- maybe 6"+ of snow fell, but wind may have stripped it from the station's depth gauge.

Rabbit Ears Pass: 3-7" Forecast Actual1" ❌️

1" Dec 7 5am (SNOTEL)
0" Dec 8 5am (SNOTEL)

Snowy Range*: 1-5" Forecast Actual7" 💥️

6" Dec 7 5am (Estimated)
1" Dec 8 5am (Estimated)

Steamboat S.A.: 3-7" Forecast Actual2" ❌️

1" Dec 7 5am (Official)
1" Dec 8 5am (Official)

Southern Colorado / NM
15/35pts (42%) ✔️5/7 (71%) 💥2/7 (28%) 0/7 (0%)

Cuchara*: 0" Forecast Actual0" ✔️

5pts
0" Dec 7 5am (Estimated)
0" Dec 8 5am (Estimated)

Purgatory: 1-4" Forecast Actual5" 💥️

3" Dec 7 5am (Official)
2" Dec 8 5am (Official)

Red Mountain Pass: 3-7" Forecast Actual9" 💥️

8" Dec 7 9am (SNOTEL)
1" Dec 8 5am (SNOTEL)

Silverton S.A.*: 3-7" Forecast Actual7" ✔️

2pts
6" Dec 8 5am (Estimated)
1" Dec 8 5am (Estimated)

Taos S.A.: 0-1" Forecast Actual0" ✔️

4pts
0" Dec 7 5am (Official)
0" Dec 8 5am (Official)

Telluride S.A.: 3-7" Forecast Actual6" ✔️

2pts
6" Dec 7 5am (Official)
0" Dec 8 5am (Official)

Wolf Creek: 0-3" Forecast Actual2" ✔️

2pts
0" Dec 7 5am (Official)
2" Dec 8 5am (Official)