• Backcountry Avalanche Forecast
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Tue, Dec 10, 2019 at 7:43 AM
Issued by: Jason Konigsberg

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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.
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Summary

You can trigger large avalanches that break near the ground on northerly and east-facing slopes. A recent avalanche near Rabbit Ears Pass (click here) on Sunday show us that these avalanches will break wide and to the ground and will be capable of burying a person. New snow amounts of over a foot in many places with up to two feet north of Steamboat will put our snowpack to the test.

Avoid steep slopes that face a northerly or east direction, especially where new snow amounts exceed a foot. Shooting cracks and sounds of collapsing are sure signs of unstable snow. You can trigger avalanches from beneath the slope or from a distance. Be careful with your terrain choices and adhere to cautious route-finding to build in a safety buffer, giving steep slopes a wide berth.

 

Avalanche Problem

 
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N
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E
W
NW
NE
SE
SW
Above Treeline
Near Treeline
Below Treeline
Certain
Very Likely
Likely
Possible
Unlikely
Historic
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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.

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


Storm Slab avalanches release naturally during snow storms and can be triggered for a few days after a storm. They often release at or below the trigger point. They exist throughout the terrain. Avoid them by waiting for the storm snow to stabilize.

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) 8 to 13 20 to 25 8 to 13
Wind Speed (mph) 10 to 20 8 to 18 12 to 22
Wind Direction WSW WSW W
Sky Cover Partly Cloudy Increasing Overcast
Snow (in) 0 0 to 1 1 to 4

Archived Forecasts

  • Select Forecast: Valid

Tue, Dec 10, 2019 at 8:12 AM
Issued by: Jason Konigsberg Statewide Weather Forecast  

The last storm left the Northern Mountains with anywhere from 6 to 12 inches of snow. Parts of the Steamboat zone, from Rabbit Ears to Buffalo Pass picked up anywhere from 14 to 24 inches. Along with all of this new snow came strong west to northwest winds. The combination of snow and wind is surely testing weak layers buried in our snowpack.

And a variety of weak layers we have. Old October snow turned into depth hoar and sits at the base of our snowpack. This is generally on shady slopes and east-facing slopes. Also we have several weak layers buried in the middle and upper portions of the pack. These layers are near-surface facets and even layers of surface hoar. These mid to upper pack layers spread around the compass to southerly slopes as well. On southerly slopes, particularly southeast, facets sits on melt-freeze crusts, providing a potential failure layer for newly wind-drifted snow. We haven't seen much avalanche activity on these sunny slopes yet, but caution is advised with the addition of wind-drifted slabs on Monday and continuing through today.

Although we haven't seen avalanches on sunny slopes, we have seen numerous avalanches on our shady and east-facing slopes. Sadly, one such avalanche resulted in the death of a skier near Cameron Pass. Conditions around Cameron Pass are not much different than other parts of the Northern Mountains region. Thick slabs of wind-drifted snow sit on numerous faceted layers and then large depth hoar at the ground.

On Monday a skier was nearly caught in an avalanche near Berthoud Pass. There have also been reports of remotely triggered avalanches from Vail Pass to Rabbit Ears Pass. All of this activity on its own should give us pause. The snowpack is reactive, avalanches are happening, and the loading from wind continues. Stick to conservative terrain choices for time being and make sure to heed obvious signs of unstable snow such as recent avalanches, shooting cracks in the snow and sounds of the snowpack collapsing.

 


  • Remotely triggered avalanche near Rabbit Ears Pass (12.8.19) (full)
  • Basal Facets. Rabbit Ears Pass on December 4, 2019. (full)
  • Two persistent layers mid snowpack. Rabbit Ears Pass on December 4, 2019 (full)

See more photos & videos

Five Day Trend

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Avalanche Observations
Report Date # Elevation Aspect Type Trigger SizeR SizeD
View Sun Dec 8 - <TL NE SS AS / r R3 D1.5

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Field Reports
Report Date Observer Snowpack Obs Avalanches Media
View Mon Dec 9 - No Yes (1) Yes (1)

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Weather Observations
Station Date Time Temperature Relative Humidity Wind Speed Wind Direction Max Gust 24 Hr Snow
Bear River Wed Dec 11 1:00 AM 14 - - - - 1.0
Steamboat Lake State Park Wed Dec 11 2:00 AM 1 91 0 34 1 0.2
Crosho Wed Dec 11 1:00 AM 13 - - - - 1.0
Lost Dog Wed Dec 11 1:00 AM 22 - - - - -
Ripple Creek Wed Dec 11 1:00 AM 15 - 0 102 - -
Storm Peak Observatory Wed Dec 11 2:00 AM 12 100 9 181 10 -
Trapper Lake Wed Dec 11 1:00 AM 19 - - - - 1.0
Tower Wed Dec 11 1:00 AM 15 - 5 203 - -
Zirkel Wed Dec 11 1:00 AM 23 - - - - -

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