In terrain above 3,500’, the last storm cycle laid down mostly snow (as opposed to rain). Terrain above this elevation is harboring old wind slabs up to a foot in depth. These slabs are resting on weak interfaces. It is on steep upper elevation leeward slopes where you are most likely to encounter unstable snow today. The likelihood of triggering an old wind slab is on the lower end of the scale but cannot be ruled out.
We got a good observation from the Divide creek area yesterday. A shallow layer of facets is somewhat reactive to pit tests. Same for the well developed facets at the ground. Overall these are only moderate concerns, but should be taken into consideration when out in the backcountry.
Slabs 3-6 feet thick are sitting on weak snow near the ground in the upper elevations. It is less likely to trigger a deep slab today in comparison to a more shallow old wind slab or persistent slab. However, the possibility remains for triggering a slab that can pull out snow to the ground. Unlike the persistent (old) wind slab concern, deep slabs have the potential to move large volumes of snow. Avoiding likely trigger points, especially areas where slabs are thinner, will lower the likelihood of triggering a deep slab avalanche today.
This problem is not a concern below 3000 feet where the previously water saturated layers have now frozen into a very strong and stable crust layer.
In case you’re just tuning in, we have a very thick crust in the forecast area. This “bulletproof” crust exists on all aspects up to 3,500’ in elevation, and is over 2 feet thick in places. Travel in steep terrain warrants extra caution, as arresting a fall is very challenging at this time.
Expect all of these issues to remain until a shift in the weather pattern takes place and surface conditions change.
Clear skies, light wind, and average winter temperatures (20s F) have been the weather over the last couple days. This trend will continue through today and transition to something a little different this evening.
The National Weather Service is issuing a Winter Weather Advisory for Friday morning to Saturday morning for blowing snow that may reduce visibility and make travel difficult. This is due to a forecasted 2-6 inches of cold dry snow with moderate to strong wind.
|04/19/21||Turnagain||Avalanche: Triangle, Seattle creek||Will Morrison|
|04/18/21||Turnagain||Avalanche: Turnagain Pass Road Obs||Andy Moderow|
|04/18/21||Turnagain||Observation: Seattle Ridge, approximately 300 yards south of the up track||Brent Byrne|
|04/17/21||Turnagain||Avalanche: Road obs||Johnston-Bloom / Moderow Forecaster|
|04/16/21||Turnagain||Avalanche: Seattle Ridge||Wendy Wagner Forecaster|
|04/16/21||Turnagain||Avalanche: Turnagain Pass, non-motorized side seen from Seattle Ridge||CNFAIC Staff Forecaster|
|04/16/21||Turnagain||Observation: Sunburst||Lance breeding|
|04/15/21||Turnagain||Observation: Tincan||Schauer/ Rothman Forecaster|
|04/13/21||Turnagain||Observation: Turnagain Pass Road Obs||A Schauer Forecaster|
|04/12/21||Turnagain||Observation: Tincan||Johnston-Bloom / Latosuo 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.