|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.
The pictures below show an example of our primary concern. Wind slabs have been reactive to natural and human triggers over the last few days. After yesterday’s calm weather it will be less likely to find this problem today. It may be possible to find reactive wind slabs in steep and complex terrain greater than 35 degrees.
Patterns of recent wind slabs have shown mostly small avalanches, breaking 6-18 inches deep. A mid-elevation band between 2000 and 2500 feet places the wind slab on top of a slick melt/freeze crust. I’m more concerned about terrain above 3000 feet today because that’s where we find more of our steeper pitches. Cross loaded steep gullies in consequential terrain on all aspects should be treated with respect.
Cornices are another form of windslab, with an unsupported overhanging nature. Now that we’ve reached mid winter, cornices are getting large and mature. As always, they should never be trusted and only approached with caution. The wind slab in the pictures was likely triggered by a naturally failing cornice.
No snow yesterday, mostly sunny skies, pleasant temperatures in the mid to high 20s, and light wind made for a great day in the mountains.
Today, a few inches of snow is forecasted this morning. Temperatures should be just below freezing at sea level. Wind is expected to be 10mph or less. Snowfall will decrease this afternoon leaving mostly cloudy skies.
A blizzard watch is in effect starting Thursday afternoon. Stay tuned as we track the development of this storm.
Graham will issue the next advisory tomorrow morning, February 7th.
|Dalpes/Thamm/ Schauer Forecaster
|Avalanche: Base of Seattle Ridge
|Troy Tempel, Thomas Lees, .Josh Bollaert, Damian Naquin
|Observation: Lynx creek
|Observation: Tincan Trees
|Moderow / Clayton
|Observation: Turnagain (below the uptrack)
|Alaska Avalanche School Moto Level 2
|John Sykes Forecaster
|Observation: Tincan Backdoor, Center Ridge
|AAS Level 1 / R Sullivan
|Avalanche: Tincan Trees
|Schauer/ Moderow/ Stephenson Forecaster