It has been over a week since a large avalanche was triggered on Pastoral by two skiers traveling below the NW face. If you have been reading the forecast regularly we are not trying sound like a broken record but the message is the same. This snow pack set-up continues to warrant elevated caution and respect. It is a high consequence avalanche problem that is impossible to outsmart and can take a long time to heal. The ingredients for a deep slab avalanche have been found in the upper elevations of our forecast zone, above 3000’ on slopes that did not avalanche in the early December storm cycle. This is a hard slab, 3-5+ feet thick, sitting on top of weak sugary snow (basal facets) near the ground. Observations over the last few weeks indicate this poor structure is widespread across our region in the alpine elevations.
When dealing with a deep slab avalanche problem, keep in mind:
Over the last two weeks we have been trying to inventory terrain that has or has not avalanched like this observation sent yesterday from Seattle Creek. Photo taken and annotated by Peter Wadsworth. Check out his observation HERE.
Cold temperatures and stable weather this week have been making the snow more brittle and faceting out surfaces. With that said triggering an old wind slab is still possible on very steep terrain in the alpine zone. Places you might find a hard wind slab will be in steep couloirs, large unsupported terrain features, or in thin rocky areas. Triggering a wind slab in the Treeline zone is becoming less likely, but is not out of the question in high consequence terrain. This also goes for a few inches of fast moving loose surface snow “sluff” that could catch you by surprise if you’re not expecting it. Triggering a wind slab could take you for an undesirable ride, and has the potential for initiating a much larger and more dangerous avalanche above 3000′. Be suspect of any slopes that may harbor a deep slab problem in the upper elevations as described above.
Thin wind slab crowns from a wind event that ended Dec.24 were seen on North and West aspects in Seattle Creek yesterday, as well loose surface snow. Photo by Peter Wadsworth.
Yesterday skies were mostly clear and temperatures along ridgetops averaged in the teens (F) with pockets of colder air at valley bottoms. Valley fog was present along Turnagain Arm. Winds were light and variable and no precipitation was recorded. Overnight thin cloud cover has moved into the region
Today skies are expected to be overcast with light Easterly winds. Temperatures should remain in the mid teens (F) to low 20F’s along ridgetops. Snow flurries are possible, but only a trace of snow is expected.
A big pattern change is on tap for this weekend. Snow should start falling on Saturday with the intensity picking up late Saturday evening into Sunday morning. Several feet of snow is possible for the Kenai Mountains. Strong Easterly winds are expected as well as rapidly rising temperatures which could change snow to rain at lower to mid elevations as the storm progresses.
|Temp Avg (F)||Snow (in)||Water (in)||Snow Depth (in)|
|Center Ridge (1880′)||20||0||0||30|
|Summit Lake (1400′)||8||0||0||12|
|Alyeska Mid (1700′)||17||0||0||26|
|Temp Avg (F)||Wind Dir||Wind Avg (mph)||Wind Gust (mph)|
|Seattle Ridge (2400′)||17||variable||3||14|
|01/25/20||Turnagain||Observation: Tincan||Eric Roberts/ Kakiko|
|01/23/20||Turnagain||Observation: TIncan||Eric Roberts|
|01/23/20||Turnagain||Observation: Goldpan||Allen Dahl|
|01/22/20||Turnagain||Observation: Sunburst||Adrian Beebee|
|01/22/20||Turnagain||Observation: Sunburst||Ryan Van Luit Forecaster|
|01/22/20||Turnagain||Observation: Seattle Ridge||W Wagner Forecaster|
|01/22/20||Turnagain||Observation: Tincan||Allen Dahl|
|01/21/20||Turnagain||Observation: Tincan||Eric Roberts|
|01/20/20||Turnagain||Observation: Eddies||H. Thamm B. Edwards|
|01/20/20||Turnagain||Observation: Eddies||Andy Moderow|
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: firstname.lastname@example.org
|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.