As sunny skies and calm weather remains over the area, the snowpack continues to adjust to the impacts of the high winds last week. It has now been 11 days since the last snowfall. Although we are still finding poor structure on slopes above the trees that have not avalanched, the slab continues to lose its reactivity in pits and there has not been a human triggered avalanche for a week. There are several weak layers sitting under the old hard wind slabs; these are facets and buried surface hoar in the mid-pack and facets at the base of the pack. Check out the video below for a look at a suspect trigger point (thin rocky area on an unsupported slope) from yesterday.
The one change in weather today is the warming at the upper elevations. Check out the graph below of the Sunburst weather station at 3,812′ that hit 39F this morning! Will this be enough warming to impact the surface conditions, or the slab? Likely not too much since the atmosphere is so dry and skies are clear (allowing the snowpack to radiate its warmth back into space).
Surface conditions? Riding and skiing has been reported to be nice, yet bottomless, in areas below treeline in soft ‘recycled’ powder. Above treeline, surface conditions are variable: wind affected hard/old slabs, anti tracks, sastrugi, breakable wind crust, and in some areas, interspersed with soft old faceted snow.
As always, keep a lookout for whumphing and cracking in the snow. These are signs you found a slab that remains unstable and again a good reason to keep up safe travel protocol (expose one person at a time, group up in safe zones and have an escape route planned).
Pastoral Peak: Fairly well distributed grains of shale and dirt covering the Pastoral Glacier; an indication of how strong the winds were during the Dec 29 and Jan 5th wind events. (Photo: S. Galoob & J. Haffener)
Glide avalanches are possible this week: The warm temperatures at the upper elevations may enhance ‘glide’ in the snowpack. Watch for glide cracks to open up and a few may release. This pattern is similar to last week when 3 glide cracks released. Known cracks exist on the South face of Eddie’s, Goldpan (behind the Magnum ridge), East face of Seattle Ridge (Northern end) and Southerly slopes near Johnson Pass.
Glide avalanche in Lynx creek from January 2nd
Sunny skies – calm winds and an impressive inversion is over the region! Yesterday we saw temperatures in valley bottoms between -5 and 5F where at the 3,500′ ridgelines it was 35F (balmy). Winds were light and variable.
Today, upper elevation temperatures will be even warmer – overnight Sunburst weather station reports temperatures rising to 39F. Valley bottoms will remain cold, in the single digits, and ridgetops in the mid 30’sF. Winds are forecast to be 5-10mph from a Northerly direction and skies clear.
This pattern looks to persist through the week – but….. models are showing the blocking high pressure eroding by the end of the week and chance for precipitation this weekend.
|Temp Avg (F)||Snow (in)||Water (in)||Snow Depth (in)|
|Center Ridge (1880′)||19||0||0||34|
|Summit Lake (1400′)||7||0||0||11|
|Alyeska Mid (1700′)||21||0||0||22|
|Temp Avg (F)||Wind Dir||Wind Avg (mph)||Wind Gust (mph)|
|Seattle Ridge (2400′)||32||N||3||8|
|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.