• Backcountry Avalanche Forecast
  • Forecast Discussion
  • Observations & Weather Data

Tue, Dec 10, 2019 at 7:20 AM
Issued by: Mike Cooperstein

Today

 

Tomorrow

Considerable (3) Dangerous avalanche conditions. Cautious route-finding and conservative decision-making essential.   Moderate (2) Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully.
Considerable (3) Dangerous avalanche conditions. Cautious route-finding and conservative decision-making essential.   Moderate (2) Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully.
Considerable (3) Dangerous avalanche conditions. Cautious route-finding and conservative decision-making essential.   Moderate (2) Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully.
  Danger Scale

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Summary

New snow and strong northwesterly winds over the last 24-hours are creating dangerous avalanche conditions. Travel on and under steep northerly and easterly-facing slopes is not recommended in any elevation band. You can trigger avalanches from a distance or from below slopes. If you trigger an avalanche in one of these areas it will most likely break at the ground and entraining the entire season's snowpack. These avalanches will be large enough to bury and possibly kill you.

On high elevation east and southeast-facing slopes recent winds have thickened and stiffened slabs over a series of crusts and weak snow. Look for and avoid any area where you find hard hollow sounding snow, dense pillows of snow, and avoid travel on any steep slopes where you see fresh cornice growth. 

The Gunnison zone a complex snowpack with weak layers in the upper, middle, and bottom of the snowpack. These weak layers exist across many aspects and elevations. Stick to lower angle terrain without steep locally connected slopes above you until the snowpack has time to adjust to the new load. Sticking to wind sheltered areas is not a guarantee for safety. 

 

 

Avalanche Problem

 
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N
S
E
W
NW
NE
SE
SW
Above Treeline
Near Treeline
Below Treeline
Certain
Very Likely
Likely
Possible
Unlikely
Historic
Very Large
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Avalanche Character Aspect/Elevation Likelihood Size

What You Need to Know About These Avalanches


Persistent Slab avalanches can be triggered days to weeks after the last storm. They often propagate across and beyond terrain features that would otherwise confine Wind and Storm Slab avalanches. In some cases they can be triggered remotely, from low-angle terrain or adjacent slopes. Give yourself a wide safety buffer to address the uncertainty.

Avalanche Problem

 
problem icon
N
S
E
W
NW
NE
SE
SW
Above Treeline
Near Treeline
Below Treeline
Certain
Very Likely
Likely
Possible
Unlikely
Historic
Very Large
Large
Small
Avalanche Character Aspect/Elevation Likelihood Size

What You Need to Know About These Avalanches


Wind Slab avalanches release naturally during wind events and can be triggered for up to a week after a wind event. They form in lee and cross-loaded terrain features. Avoid them by sticking to wind sheltered or wind scoured areas.

Avalanche Problem

 
problem icon
N
S
E
W
NW
NE
SE
SW
Above Treeline
Near Treeline
Below Treeline
Certain
Very Likely
Likely
Possible
Unlikely
Historic
Very Large
Large
Small
Avalanche Character Aspect/Elevation Likelihood Size

What You Need to Know About These Avalanches


Persistent Slab avalanches can be triggered days to weeks after the last storm. They often propagate across and beyond terrain features that would otherwise confine Wind and Storm Slab avalanches. In some cases they can be triggered remotely, from low-angle terrain or adjacent slopes. Give yourself a wide safety buffer to address the uncertainty.

Weather Forecast for 11,000ft Issued Tue, Dec 10, 2019 at 12:45 PM by Jason Konigsberg Statewide Weather Forecast
  Tuesday Night Wednesday Wednesday Night
Temperature (ºF) 5 to 10 25 to 30 5 to 10
Wind Speed (mph) 8 to 18 5 to 15 5 to 15
Wind Direction W WSW WNW
Sky Cover Mostly Clear Increasing Mostly Cloudy
Snow (in) 0 0 0 to 1

Archived Forecasts

  • Select Forecast: Valid

Tue, Dec 10, 2019 at 8:02 AM
Issued by: Matt Huber Statewide Weather Forecast  

Snow kept falling yesterday around the Central Mountains, bringing snow totals to well over a foot in many areas. Winds will have plenty of fresh, low-density snow to load onto leeward slopes, stressing a snowpack that proves to be weak already. As the cold front passed, winds shifted to the northwest and built fresh slabs onto many slopes, including southeast- facing slopes. Although it may not stress the buried melt-freeze crusts and facet combinations that linger deeper in the snowpack on these sunnier aspects, these fresh wind-slabs are likely to be tender. 

The continued snow made for some good riding yesterday but visibility was so poor that we have been unable to verify our forecasts with any real confidence. Although given the weak structure, slabs over persistent weak layers, and the continued reports of a collapsing snowpack and shooting cracks, most CAIC forecasters were confident that triggered avalanches remain likely today. The threat of natural avalanche’s is largely over, but not out of the question. As the skies clear and visibility improves, we will be able to assess how widespread the natural cycle was, if at all.

The threat of remotely triggered avalanches remains constant, with new reports coming in almost daily. Approach steep terrain with the assumption that you can trigger an avalanche without being on the slope, and you won’t be surprised when you do.


  • A small avalanche below treeline that illustrates multiple layers of buried Surface Hoar. 12/6/19 (full)
  • A fracture that initiated in an upper-snowpack weak layer below the cliffs, that stepped to a lower mid-pack weak layer, before gouging down into the old October snow further down the bed surface. 12/6/19 (full)
  • A southeast facing slope with a broad Persistent Slab avalanche. Augusta Peak. 12/6/19 (full)
  • A broad avalanche with fracture lines connecting from near the summit down through the cliffs into the shadows. Schuylkill Peak. 12/6/19 (full)
  • A large west-facing avalanche off Cinnamon Mountain. This slide is estimated to have run on 12/5/19. (full)

See more photos & videos

Five Day Trend

Saturday

Sunday

Monday

Today

Tomorrow

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Avalanche Observations
Report Date # Elevation Aspect Type Trigger SizeR SizeD
View Tue Dec 10 - - SE SS N R2 D1.5
View Tue Dec 10 - >TL E SS N R2 D2
View Tue Dec 10 - >TL E SS N R2 D2
View Tue Dec 10 - >TL SE SS N R2 D2
View Tue Dec 10 - >TL SE SS N R1 D1
View Tue Dec 10 - >TL NE SS - R2 D2
View Mon Dec 9 - >TL E U N R1 D2
View Mon Dec 9 - <TL NE U U R2 D1.5
View Sun Dec 8 - TL NE SS AS / r R1 D1

See All Avalanche Observations

Field Reports
Report Date Observer Snowpack Obs Avalanches Media
View Tue Dec 10 Eric Murrow No Yes (1) Yes (3)
View Tue Dec 10 Sam Roberts No No Yes (1)
View Tue Dec 10 Ben Pritchett No Yes (5) Yes (6)
View Mon Dec 9 Crested Butte Avalanche Center No No Yes (3)
View Mon Dec 9 Evan Ross No No No
View Mon Dec 9 Alex Tiberio No Yes (2) Yes (2)
View Sun Dec 8 Crested Butte Avalanche Center Yes (1) Yes (1) Yes (2)
View Sun Dec 8 Ian Havlick No No No

See All Field Reports

Weather Observations
Station Date Time Temperature Relative Humidity Wind Speed Wind Direction Max Gust 24 Hr Snow
Butte Wed Dec 11 1:00 AM 15 - - - - -
Park Cone Wed Dec 11 1:00 AM -1 - - - - -
Taylor Park Wed Dec 11 1:57 AM 4 85 2 120 4 -

See All Weather Observations