Yesterday was the second day since the surface hoar was buried on November 17th that we haven’t received any reports of human triggered slab avalanches in Turnagain Pass. With time this layer of buried surface hoar is becoming more stubborn and less reactive but this also means the slab has the potential to fracture once well onto the slope. This layer hasn’t gone away and still needs to be a major factor in slope choice. Remember buried surface hoar is persistent weak layer and human triggered avalanches are still possible. Observations around Turnagain pass continue to show that this layer is widespread throughout the terrain. Dozens of human triggered and remote triggered avalanches have occurred since November 17th on the popular slopes of Tincan, Sunburst, and Magnum. These avalanches have been small to medium in size; just large enough to bury a person or seriously injure you in a ride. Larger and/or steeper, more wind-loaded slopes that haven’t been ridden still have potential to avalanche and could have high consequences because of this weak layer. This is important to keep in mind today and throughout the weekend with more snow heading our way. Today new snow and wind increasing late in the afternoon may cause the danger level to rise. Pay attention to changing conditions, additional load will only make the consequences even larger. Be on the lookout for obvious signs of instability like blowing snow, shooting cracks and whumphing sounds. In addition new snow and wind will be loading weak surface snow (new layer of surface hoar and near surface facets) that has developed over the past few cold clear days and may be reactive at this interface as well.
With the holiday weekend there could be more people heading into the backcountry. Be extra aware of other groups above and below you and only expose one person on a slope at a time.
National Avalanche Center Danger Scale tutorial: HERE.
Buried surface hoar found easily in a snow pit on Tincan yesterday at 2700′. Photo: Andy Moderow
There were two glide avalanches reported on November 23rd and other glide cracks have been observed around Turnagain and Summit area. If you see a glide crack give these a wide berth, minimize time spent underneath, and remember these are totally unpredictable. They are not triggered by humans and are the entire snowpack releasing. These will also be hard to see when covered up by new snow and wind loading.
Glide crack opening on the face of Common Bowl on Tincan. Photo: Andy Moderow
…WINTER WEATHER ADVISORY FOR BLOWING SNOW REMAINS IN EFFECT
FROM 5 PM THIS AFTERNOON TO 5 AM AKST SUNDAY THROUGH TURNAGAIN
PASS AND PORTAGE VALLEY… See link HERE for more details.
Yesterday started with light snow in the morning with a inch of accumulation. Skies cleared in the afternoon and valley fog moved in late in the day. Temperatures were in the low 20Fs. Winds blew easterly in the 20s in the morning and shifted to northerly and light in the afternoon. Overnight the temperatures dipped into the teens and the winds were light.
Today will be partly to mostly cloudy as the storm approaches. Snow is expected to start this afternoon and winds are forecasted to pick up gusting into the 30s from the SE. 0-3″ of snow is possible. Temperatures should rise to the high 20Fs. Tonight the snowfall and wind will continue with 5-10 inches forecasted to fall and gusts into the 40s. Temperatures should remain in the 20s.
Tomorrow temperatures should dip back down to low 20Fs. Winds should become light and northerly and there is still a chance of light snow. There is a bit of clearing trend into the middle of the week and then more snow on tap for the weekend.
|Temp Avg (F)||Snow (in)||Water (in)||Snow Depth (in)|
|Center Ridge (1880′)||19||1||.1||18|
|Summit Lake (1400′)||21||1||.1||3|
|Alyeska Mid (1700′)||20||0||0||3|
|Temp Avg (F)||Wind Dir||Wind Avg (mph)||Wind Gust (mph)|
|Seattle Ridge (2400′)||16||variable||15||30|
|05/06/20||Turnagain||Avalanche: Pastoral Peak, north face||Andy Duenow|
|04/10/20||Turnagain||Avalanche: Wolverine||Mike Records|
|04/10/20||Turnagain||Observation: Eddies lookers right shoulder||Matt Yoder|
|04/09/20||Turnagain||Observation: Bench Peak||Mike Records|
|04/04/20||Turnagain||Observation: Pete’s North||Anonymous|
|03/26/20||Turnagain||Avalanche: Tincan – Proper (SW facing)||CNFAIC Staff|
|03/26/20||Turnagain||Avalanche: Seattle Ridge||W Wagner Forecaster|
|03/25/20||Turnagain||Avalanche: Sunburst Uptrack @ 2000′||J. Boisvert|
|03/24/20||Turnagain||Observation: Turnagain – Road Observations||W Wagner Forecaster|
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.