It was a quiet day in the backcountry yesterday (avalanche-wise) though many folks were out continuing to enjoy the sunny weather and Friday’s unexpected 14-18” refresher. The last avalanche reported on the Pass was Monday, two days ago, where a snowboarder triggered a soft slab in Seattle Creek. Otherwise, there have been a few reports of remote triggered shallow slabs Sunday and Monday north of the Pass (20mile area) as well as south (Grandview region).
The main concern for today continues to be triggering one of these persistent soft slab avalanches. These slabs have been in the 12-20″ range and are sitting on a thin layer of faceted snow over a crust. It is interesting how spatially variable both the slabs are as well as the thin layer of faceted snow underneath. Many areas simply have no slab at all, only loose unconsolidated snow. Yet in other areas, people are still finding snow with just enough slab character to trigger an avalanche. If you didn’t read it yesterday, check out this great article on spatial variability by Ron Simenhois (inventor of the very popular ECT test). This is one of those set-ups that can lull us into complacency. Just because the ridge next to you was tracked-out without incident doesn’t necessarily mean yours is good to go. Every slope should be evaluated on its own, especially if you are venturing into steeper and more complex terrain where triggering even a small slab could have higher consequences. Watching for cracking or collapsing as well as performing hand pits, proper ski cuts and having an escape route planned are ways to manage this issue.
Loose snow avalanches, or sluffs, are becoming easier to initiate as the top foot+ of snow continues to become looser by the day. The past four days of clear and cold conditions are eating away (or faceting) Friday and Monday’s snow. Sluffs yesterday were mainly low volume, predictable and confined to slopes around 40 degrees and steeper. With continued cold temperatures, watch for these to start entraining more snow and run further.
The deep slab issue is still of concern in the upper most elevations of our forecasting zone. The likelihood of triggering a full depth avalanche breaking in weak snow near the base of the pack is low but the consequences remain high.
This problem is not a concern below 3000ft where the previously water saturated layers have now frozen into a very strong and stable layer.
Sunshine, light variable winds and single-digit temperatures prevailed again yesterday. Overnight, skies have remained mostly clear and the temperatures have plummeted – minus single digits are being seen at all elevations: -5 to -10F at sea level and -2F on the ridgetops. Winds are still light from a Northerly direction around 3-5mph.
For today, mostly clear skies will be replaced with clouds and a chance for a falling snow crystal or two. Temperatures will continue to be cold and may even reach the minus double digits in valley bottoms – burrr. The good news for anyone venturing out today is the wind will be light from the North, ~5mph or less. This may not help to warm things up however if the clouds keep the sun at bay.
For tonight and into tomorrow there is a chance for snowfall as a large area of low pressure develops in the Northern Gulf spreading small amounts of moisture our way. However, the temperatures remain below 0F which is not an ideal set up for snow accumulation. But, we can hope for the best, which would be around 4-5″ by Thursday night.
Check out this graphic by the NRCS. It shows general snowpack depth for the state as of February 1st. Yes, too much red…
|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: email@example.com
|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.