|Sun, February 11th, 2024
|Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features.
|Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern.
|Dangerous avalanche conditions. Careful snowpack evaluation, cautious route-finding, and conservative decision-making essential.
|Very dangerous avalanche conditions. Travel in avalanche terrain not recommended.
|Extraordinarily dangerous avalanche conditions. Avoid all avalanche terrain.
|Likelihood of Avalanches
|Natural and human-triggered avalanches unlikely.
|Natural avalanches unlikely; human-triggered avalanches possible.
|Natural avalanches possible; human-triggered avalanches likely.
|Natural avalanches likely; human-triggered avalanches very likely.
|Natural and human-triggered avalanches certain.
|Avalanche Size and Distribution
|Small avalanches in isolated areas or extreme terrain.
|Small avalanches in specific areas; or large avalanches in isolated areas.
|Small avalanches in many areas; or large avalanches in specific areas; or very large avalanches in isolated areas.
|Large avalanches in many areas; or very large avalanches in specific areas.
|Very large avalanches in many areas.
Two small human triggered wind slabs were reported on Hatch Peak and Marmot on Friday as a result of increasing wind throughout the day. No other significant slab avalanches have been observed or reported since January 19th.
Numerous natural and human triggered dry loose avalanches (sluffs) were observed in steep terrain greater than 40º on all aspects this week. Most of the avalanches were small and inconsequential with a few large sluffs observed in isolated and extreme terrain. Most of the activity occurred earlier in the week during the spell of cold temperatures.
|Size (D scale)
|Unlikely to bury a person
|Can bury a person
|Can destroy a house
|4 & 5
|Can destroy part or all of a village
Strong wind at upper elevation was observed by numerous backcountry users and increased throughout the day on Friday, transporting just enough snow to build small wind slabs. As predicted , Southeast winds have increased overnight and at 6 am are reporting 30-37mph gusting 44-53 mph at 4500ft over the past 7 hours. Winds are expected to remain steady throughout the day and contribute to today’s avalanche problem.
After nearly two weeks of mostly low danger with very few avalanche problems, the paradigm is shifting. 5 to 10 inches of new snow is expected by early Sunday morning. If we receive the higher end of precipitation expect to see an increase in avalanche activity on Sunday.
It will be possible to human trigger wind slabs up to 12 inches thick on Southwest to Northeast aspects above 3500 ft. Expect wind slabs to grow in size and sensitivity throughout the day as winds persist. Winds are expected at to be strongest at upper elevations. Pay attention to specific terrain features like leeward aspect gaps, passes, and cross loaded slopes where triggering a wind slab will be more likely today. Triggering a wind slab below 3500 ft is unlikely.
Use hand pits and pole probes to identify wind slabs. Look for hard snow sitting over weaker snow, smooth and rounded or lens shaped features. Shooting cracks or whumping are signs of instability and indicators of this avalanche problem.
As always we recommend carrying the appropriate rescue gear and knowing how to use it. Safe travel techniques are important every time we travel in avalanche terrain. This means spreading out when ascending slopes, descending one at a time, and regrouping well outside of the runout zone.
Triggering small to large sluffs was more likely earlier in the week during the cold spell of weather. Over the past several days temperatures have warmed up considerably. Temperatures in the mid-twenties combined with warm storm snow on 2/4 has left snow surfaces more cohesive with a subtle upside down feel. Expect to find more variability with snow conditions today and the best powder on colder protected aspects not affected by the wind.
Triggering a small sluff in isolated locations still remains possible in 40º and steeper terrain on all aspects and all elevations.
Even a small loose dry avalanche may be able to sweep you off your feet and carry you into other hazards. Small dry loose avalanches can be mitigated safely with appropriate slope cutting techniques.