By far the most common problem is related to recent snow on top of the prominent crust layer. The 16+ inches that Turnagain Pass received on February 7th have been responsible for many reported avalanches since that storm. The general trend of these avalanches is – small in size (12-20″ deep), lower volume, decent propagation across wind stiffened steep slopes. Check out the observations page for a bunch of photos from the last 6 days, and this observation for a good quick synopsis of the problem.
The 2 properties necessary to create avalanches that are not always found –
1. A cohesive slab – some wind loading and stiffening is necessary to create connectivity of the surface snow, otherwise it’s just loose powder with sluff potential.
2. A faceted interface between the new snow (Feb 7th storm) and the underlying crust (January melt/freeze) or old snow. In places where the facets are present, this is a significant weak layer consisting of large loose grains with poor bonding.
Cold high pressure from early in the week has transitioned to a showery precipitation pattern as of yesterday afternoon. A few inches of fresh light powder have fallen since Wednesday. Temperatures remain quite cold, especially for snow to be falling, reaching into the negatives at many of our local weather stations. Wind is generally light, although since about 4am the wind has increased slightly and switched over to a East Northeast direction. Expect cloudy skies today with snow showers and 2-4 inches of snow accumulation today.
The extended forecast looks like more of this same pattern. A low pressure system is anchored over the northwestern gulf, and expected to stay there well into next week. Most precipitation from this event will be showery, but there is a chance for heavier snow events by the weekend.
|01/24/21||Turnagain||Observation: Pete’s||Mike Records|
|01/24/21||Turnagain||Observation: Triangle bowl||Cooper Street|
|01/24/21||Turnagain||Avalanche: Eddies||Johnston-Bloom / Moderow Forecaster|
|01/24/21||Turnagain||Observation: Corn Biscuit||Troy Tempel|
|01/23/21||Turnagain||Observation: Seattle Ridge||A Schauer Forecaster|
|01/23/21||Turnagain||Avalanche: Tincan Trees||Matti Silta|
|01/22/21||Turnagain||Observation: JOHNSON PASS||Anonymous|
|01/20/21||Turnagain||Observation: Sunburst||Johnston-Bloom / Roberts Forecaster|
|01/19/21||Turnagain||Avalanche: Cornbiscuit||Schauer/ Johnston-Bloom Forecaster|
|01/19/21||Turnagain||Avalanche: Sunburst and Tincan||CNFAIC Staff|
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.