Seattle Ridge: One skier was caught and carried, but not buried, after triggering a small avalanche 10” deep and 40’ wide. The skier was uninjured. More details here.
Seattle Ridge: Snowmachiners were able to trigger small wind slab avalanches failing on a layer of surface hoar buried 4-16” deep. Details and photos here.
|Signal Word||Size (D scale)||Simple Descriptor|
|Small||1||Unlikely to bury a person|
|Large||2||Can bury a person|
|Very Large||3||Can destroy a house|
|Historic||4 & 5||Can destroy part or all of a village|
The biggest concern today will be triggering an avalanche 1-2’ deep where a stiff slab rests on a weak layer of buried surface hoar and faceted snow. Thankfully, it does not look like yesterday’s winds got quite as strong as we were anticipating. Although we were spared any widespread damage, the light to moderate winds have redistributed snow into stiff slabs on some slopes, which sit on top of a weak layer of buried surface hoar and near-surface facets. We received reports of human-triggered avalanches from two different groups on Seattle Ridge (details here and here) and a third group in the Tincan Trees (details) yesterday. It is still possible to trigger an avalanche on slopes that have seen previous loading, with stiff snow at the surface today. These may be recognized from a distance by their smooth, pillowy texture, or you might notice stiffer, ‘punchy’, hollow slabs as you approach a potentially dangerous slope. This combination will sometimes– not always– show clues of instability, like shooting cracks or collapsing. If you see any of these signs of instability, choose different terrain that has not been previously wind-loaded. Sheltered terrain will have the best riding conditions anyway. With varying wind directions since our last snowfall, it is difficult to identify any kind of pattern with wind loading. Be on the lookout near ridgelines, convexities, and cross-loaded gullies on any aspect.
There are some areas for which we have limited observations from yesterday, that tend to experience stronger winds when we have these northwesterly wind events. Be extra cautious if you plan on heading out in near Crow Pass, or in the Summit Lake area, as these places may have seen stronger winds yesterday than weather stations are able to capture.
Loose Snow Avalanches (Sluffs): Continued cold and clear weather is keeping the surface snow dry and loose in areas that have been sheltered from the wind. Be aware of fast-moving and high-volume sluffs in steep terrain, especially if you are traveling near terrain traps like cliffs, rocks, trees, or gullies.
Cornices: Cracks have opened up where large cornices are peeling away from cornices. If you are traveling along ridgelines be sure to give them plenty of space, and minimize the amount of time you spend traveling below them. Cornices will fail easily under the weight of a person, and they may trigger an avalanche if they fall on a wind-loaded slope below.
Glide cracks have opened up throughout the area. These avalanches are unpredictable and they are large since they involve the entire season’s snowpack. Avoid spending any time on or below slopes with glide cracks, and if you see any new glide activity please let us know here.
Yesterday: High temperatures reached the upper teens to low 20’s F under mostly sunny skies, with some lingering valley fog through the day. Northwesterly winds were blowing 5-15 mph at the ridgetops, with gusts to 31 mph at Sunburst. Low temperatures were in the single digits below zero F at Summit Lake, and in the single digits to low teens above zero F near Girdwood and Turnagain Pass.
Today: Another day of clear skies is on tap for today as an upper level high-pressure ridge stays in place over the area. Westerly winds are expected to stay around 5-15 mph, and temperatures are expected to reach the mid- to upper teens F.
Tomorrow: Low temperatures will dip down into the single digits F tonight, and possibly below zero again near Summit Lake. Highs tomorrow are expected in the mid- to upper teens F tomorrow, with westerly winds blowing 5-10 mph. We are expecting another day of mostly sunny skies, with no precipitation.
PRECIPITATION 24-hour data (6am – 6am)
|Temp Avg (F)||Snow (in)||Water (in)||Snow Depth (in)|
|Center Ridge (1880′)||20||0||0||118|
|Summit Lake (1400′)||9||0||0||43|
|Alyeska Mid (1700′)||15||0||0||108|
RIDGETOP 24-hour data (6am – 6am)
|Temp Avg (F)||Wind Dir||Wind Avg (mph)||Wind Gust (mph)|
|Seattle Ridge (2400′)||18||NW||7||19|
|05/18/21||Turnagain||Observation: Tincan Ridge||Joe Kurtak|
|04/30/21||Turnagain||Observation: Sunburst||W Wagner Forecaster|
|04/27/21||Turnagain||Observation: Tincan Ridge||Joe Kurtak|
|04/26/21||Turnagain||Observation: Magnum||Creighton/ Hoople|
|04/25/21||Turnagain||Observation: Sunburst||Nick D'Alessio|
|04/24/21||Turnagain||Observation: Airplane obs||Johnston-Bloom / DiJulia /Hilliard Forecaster|
|04/24/21||Turnagain||Observation: Corn biscuit||Heather Johnson|
|04/23/21||Turnagain||Avalanche: Lynx Ck Drainage||W Wagner Forecaster|
|04/23/21||Turnagain||Avalanche: Sunburst||Eeva Latosuo|
|04/23/21||Turnagain||Observation: Center Ridge Turnagain pass||Joe Kurtak|
Status of riding areas across the Chugach NF is managed by the Glacier and Seward Ranger Districts, not avalanche center staff. Riding area information is posted as a public service to our users and updated based on snow depth and snow density to prevent resource damage at trailhead locations. Riding area questions contact: email@example.com
|Area||Status||Weather & Riding Conditions|
This is a general backcountry avalanche advisory issued for Turnagain Arm with Turnagain Pass as the core advisory area. This advisory does not apply to highways, railroads or operating ski areas.