|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|
We have been talking about buried weak layers for a while. Let’s take a quick inventory of the state of the snowpack. It has now been two weeks since the New Year’s Eve storm and we have been in a mostly clear and cold weather pattern. Since that storm the soft surface snow has become faceted and recently we had almost a week of on and off wind. Due to the wind, the faceted surface snow was buried in some terrain by wind slab. The last human triggered avalanche was Friday evening in Crow Pass. Where does this leave us now in relation to triggering an avalanche? Well… It is still possible and something to keep in mind if traveling in steep terrain in the Alpine. The level of wind effect has been different across the advisory area. This is a key factor in where the most hazard is. If you find yourself in a zone with very hard wind effected snow this could be sitting on very weak faceted snow below. This is the suspected set up in the avalanche on Friday. Lingering wind slabs are now persistent slabs because they are associated with buried facets. Additionally there are layers deeper in the pack (Solstice buried surface hoar and/or facets and facets with the December 9th rain crust) that have been indicating that it would be hard to trigger them at this point but not impossible. The best way to manage this uncertainty is to avoid steep slopes with hard snow over soft snow, use safe travel protocol and think about consequences. If you did trigger a large avalanche where would all the snow go? Look for signs of instability but realize you may not see them with this type of avalanche problem.
Loose snow avalanches (sluffs): On slopes out of the wind expect sluffing in steep terrain. The surface snow is becoming looser and looser by the day with the cold temperatures.
Cornices: Give cornices plenty of space and limit your exposure when passing beneath them.
Glide avalanches: Due to the unpredictable potential to release, limit your time spent under glide cracks.
Yesterday: Skies were partly cloudy with patchy valley fog and very light snow showers. Temperatures were in the single digits to low teens. Winds were westerly 5-10 mph with gusts into the 20s. Overnight temperatures were mostly in the low single digits while a few stations recorded temperatures just below 0°. Winds were light and westerly.
Today: Mostly clear skies with temperatures in the low single digits. The winds are forecast to be light and becoming calm in the afternoon. Overnight temperatures look to be slightly inverted with temperatures in the the single digits at upper elevations and around 0° or just below in valley bottoms. Winds remain calm.
Tomorrow: Sunny skies, calm winds and temperatures in the single digits. This cold and clear pattern looks to persist into the weekend until skies become cloudy Saturday evening and with a chance of snow on Sunday.
PRECIPITATION 24-hour data (6am – 6am)
|Temp Avg (F)||Snow (in)||Water (in)||Snow Depth (in)|
|Center Ridge (1880′)||6||1||0.01||38|
|Summit Lake (1400′)||4||1||0.01||15|
|Alyeska Mid (1700′)||7||4||0.04||37|
RIDGETOP 24-hour data (6am – 6am)
|Temp Avg (F)||Wind Dir||Wind Avg (mph)||Wind Gust (mph)|
|Seattle Ridge (2400′)||6||W||2||16|
|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.