|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.
Girdwood: A snowboarder remotely triggered an avalanche 2′ deep and 200′ wide on Max’s yesterday. The avalanche was on a southern aspect at 3000′. Nobody was caught or carried. More details here.
Seattle Ridge: Multiple avalanches were triggered on Seattle Ridge yesterday. This includes one small snowmachine-triggered pocket near the weather station, 3 remote-triggered slabs in Warmup Bowl, and two large remote-triggered avalanches on the front side just above the motorized lot. Some of these remote-triggers were triggered from over 100′ away from the avalanches. More details here.
|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
Our persistent weak layers that formed in the beginning in the month are still giving us cause for concern today, especially after seeing multiple avalanches in the advisory area yesterday. This includes multiple remote triggered avalanches on Seattle Ridge (details here) and a remote-triggered avalanche on Max’s (details here). While some of these avalanches were relatively small and harmless, others were large enough to carry and bury a person. A lot of this action is happening in places that have seen wind loading at some point in the past week, which means there is a stiff, cohesive slab sitting on top of weak, sugary facets. In most places this older wind slab has since been buried by 12-18″ soft snow, which makes it nearly impossible to recognize if you are not looking for it carefully.
So how can you play it safe today? Be cautious with your route finding and careful with your snowpack assessment. This means actively searching for a stiffer wind slab, possibly buried below softer snow. It doesn’t take an hour in a snowpit to do this- you can hop off your machine and notice if you feel a stiff, punchy layer under your feet. You can probe with a ski pole as you move along a skin track. It also means paying attention to red flags like shooting cracks and collapsing. In areas that haven’t been wind loaded, we have noticed the storm snow is starting to settle into a slightly stiffer layer. Be prepared to adjust your objectives if you notice signs of instability as you travel.
The most likely places to encounter a dangerous setup will be in the upper elevations near ridgelines, in gullies, and below convexities. This is exactly where we’ve seen avalanches in Tincan, Max’s, and Seattle Ridge in the past two days. Because we are dealing with persistent weak layers, it is likely a person could trigger similar avalanches today. Keep in mind we have seen multiple avalanches triggered remotely, in some cases with the nearest tracks over 100′ from the crown lines. This means it is likely a person could trigger an avalanche from above, below, or to the side of a slope. It requires extra attention with your route finding. It also demands a high level of spatial awareness- paying attention to other groups that are above you or below you.
We were really happy to see people making smart choices with terrain use yesterday on Seattle ridge. There were a ton of people out, and for the most part everyone was avoiding the steep terrain. Persistent slab problems will require some patience, and low slope angles will be the name of the game for some time.
Closeup of a crown from a small snowmachine-triggered avalanche just below the ridgeline on Seattle Ridge yesterday. The avalanche failed on facets that formed in early November, and the slab consisted of a stiff wind slab that was buried by 12-18″ soft snow. 11.27.2021.
Video describing the small snowmachine-triggered avalanche on Seattle Ridge (pictured above) and current snowpack concerns (link here):
We’re still keeping glide avalanches in the back of our mind, with the most recent activity on Lipps sometime in the past week. There are a lot of glide cracks in the area, and it is impossible to predict exactly when they will release. Glide avalanches are very large and destructive since the involve the entire snowpack. The only way to manage the problem is to limit the amount of time you spend traveling below them.
Yesterday: A thick layer of valley fog broke up by late morning, giving way to mostly sunny skies. Temperatures crawled into the single digits above 0 F, and winds stayed light with variable directions. There was a trace of snow in the morning before skies cleared. Overnight lows dropped to the single digits to teens below 0 F, getting as cold as -18 F at the Summit Creek snotel station. This must be what Lou Reed was talking about when he said “It’s so cold in Alaska, It’s so cold in Alaska”.
Today: Temperatures will struggle to get above 0 F today. Luckily winds should stay light, blowing around 5 mph out of the west at ridgetops. We should get one more day of mostly sunny skies today before a system moves in tomorrow. There may be another round of valley fog this morning.
Tomorrow: It is looking like another round of active weather is moving in tomorrow. This will start with easterly winds picking up in the early morning, blowing 25-35 mph at ridgetops and 10-15 mph at lower elevations. Temperatures will continue to climb overnight and through the day tomorrow, getting back up into the low teens F during the day. There is a lot of uncertainty with precipitation predictions, but if we do get any snow we might see the rain level creep up to around 500 feet. Models are still showing different storm tracks, so be sure to stay tuned in as we track this next system.
PRECIPITATION 24-hour data (6am – 6am)
|Temp Avg (F)
|Snow Depth (in)
|Center Ridge (1880′)
|Summit Lake (1400′)
|Alyeska Mid (1700′)
*Snow depth at Center Ridge is estimated. Alyeska stations are not yet operational for the season.
RIDGETOP 24-hour data (6am – 6am)
|Temp Avg (F)
|Wind Avg (mph)
|Wind Gust (mph)
|Seattle Ridge (2400′)
|Observation: Kickstep NE Bowl
|Observation: TinCan Backdoor/ Center Ridge
|AAS L1 Turnagain
|Avalanche: Lynx Creek
|Observation: Turnagain, Seattle, Mt Ascension
|Silverton Mountain Guides
|Observation: Tincan Trees
|Dalpes/Thamm/ Schauer Forecaster
|Observation: Seward Highway across from Johnson Pass TH
|Avalanche: Base of Seattle Ridge
|Troy Tempel, Thomas Lees, .Josh Bollaert, Damian Naquin
|Observation: Lynx creek