|Travel Advice||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.|
It was a busy sunny weekend at Turnagain Pass to round out the final days of January. Tracks can be seen for miles along the ridgelines and slopes. We had some interesting avalanche activity but luckily no one was caught up in any of it. We had one very large snowmachiner triggered slide just South of Turnagain Pass on Saturday, more on this below. There were also several cornice falls (some of which triggered slabs below) and a glide avalanche.
In the heart of our forecast zone at Turnagain Pass, cornice falls seemed to be the main event. Check out this photo of a large cornice that is thought to have released sometime Saturday night. This cornice triggered a slab avalanche below taking out three sets of tracks from the day before. Read short report HERE. Photo credit: Susan Goodwin.
Avalanche concerns in the dry snow above 2,500′ today:
Winds along the ridgetops have picked up to the 15mph range overnight with stronger gusts from the East. These winds are forecast to remain, and possibly increase, throughout the day. This is just strong enough to transport snow and form shallow wind slabs. Watch for fresh wind drifted snow and active loading. Any fresh wind slab is suspect to be touchy and on slopes ~35 and steeper could avalanche.
As seen in the photo above, these monsters are still falling (both naturally and human triggered) and have the chance for triggering an avalanche below. Limiting time under these, as well as giving them a wide berth above, is key terrain management.
With the clear skis and cool temperatures loosening the surface, sluffs on steep slopes can be expected.
Hundreds of glide cracks litter the mountains and a few of these continue to pop out and avalanche where people are recreating. One these was on Cornbiscuit over the weekend. Whether or not a crack will release is completely unpredictable and is why limiting time spent under these will be a message as long as the cracks continue to slowly open.
Glide avalanche on Cornbiscuit that released sometime in the past 36 hours. More on this HERE. Photo credit: Mike Loso.
Yesterday a report came in of a large avalanche triggered off the Johnson Pass trail in the Groundhog Creek drainage on Saturday, January 30th. We were able to investigate the slide and it was indeed very large, 3′ deep and 2500-3000′ wide. See photo and video’s below. The weak layer was buried surface hoar that sits roughtly 3′ deep in the pack in this area. We have not seen this layer anywhere else in the forecast zone. It is most likely that the surface hoar was deposited in a short break in storms on 1/26 just prior to the 3+’ of new snow that fell from 1/27-1/29. More details HERE.
We are suspect that other areas south of our core Turnagain Pass forecast area may harbor this or other weak layers.
Photo of the basin that avalanched (4,000′, West aspect).
Video taken by party that triggered slide on Saturday January 30th.
Video taken the next day by forecasters.
Yesterday saw clear skies, light easterly winds and temperatures in the 20’s F above treeline. Valleys stayed relatively cool and in the teens.
For today we could see some cloud cover stream as a weak frontal band stretches over us associated with a large trough in the Gulf. Winds picked up overnight from the East along the ridgetops to the 15mph range and may increase to the 20mph range today. Temperatures will be in the 20’s F from the valley’s to 3,500′ with only a shallow inversion in place this morning. There is a slight chance for a flurry or two late in the day.
For Tuesday night through Wednesday another system moves in that should bring snow as low as 500′. Stay tuned.
|Temp Avg (F)||Snow (in)||Water (in)||Snow Depth (in)|
|Center Ridge (1880′)||23||0||0||93|
|Summit Lake (1400′)||16||0||0||27|
|Alyeska Mid (1700′)||25||0||0||71|
|Temp Avg (F)||Wind Dir||Wind Avg (mph)||Wind Gust (mph)|
|Seattle Ridge (2400′)||23||N/A||N/A||N/A|
|11/27/23||Turnagain||Avalanche: Tincan Ridge||Schauer/ Stiassny Forecaster|
|11/26/23||Turnagain||Observation: Road report: Slide with dirt on Repeat offender||Anonymous|
|11/26/23||Turnagain||Observation: Pete’s North||Ben Sullender|
|11/25/23||Turnagain||Observation: Tincan trees||John Sykes Forecaster|
|11/21/23||Observation: Spokane Creek||John Sykes Forecaster|
|11/19/23||Turnagain||Observation: Magnum – PMS Bowl||Schauer/ Cullen/ Jonas Forecaster|
|11/19/23||Other Regions||Observation: Sunnyside/Penguin||Jose Ramos-Leon|
|11/19/23||Turnagain||Observation: Eddies||Andy Moderow|