Yesterday, the cold and sustained NW wind not only affected the ridgetops but also penetrated down to treeline in some locations. This allowed for wind slabs to form both on and off the ridgelines. These were on various aspects as the wind was being channeled in many directions by the terrain. A few of these 6-12″ slabs were triggered yesterday by people but were confined to the steeper terrain (around 40 degrees or more).
Today we should see more the same. The cold NW wind continues and though there will be less snow available for transport, we should still see shallow slabs forming. Most of these are likely to be a bit sluggish on slopes around 35 degrees but in steeper terrain expect them to release and pack more of a punch. These slabs can become quite serious in committing terrain if, for example, one gets dragged over a cliff or caught and covered in a terrain trap. Watching for current wind loading, stiff or hollow feeling snow that may crack around you will be signs you have found a wind slab. Also, watch for cross-loading in gullies and sub-ridges as these winds have been blowing well below the ridgetops during the past 24 hours.
As far as the snow surface conditions go, they are highly variable with significant wind affect at most elevations. Soft powder can still be found among the wind hardened surfaces in the more sheltered locations above 2,000’. Mostly supportable crusty conditions exist below 2,000’.
The deep freeze over us again today is helping considerably to “lock” in the snowpack as a whole (except for the wind slab problem discussed above). However, we are still concerned that in shallow areas above treeline there remains a chance a person could trigger a slab avalanche breaking near the ground. Keeping with good travel practices – exposing only one person at a time, moving efficiently through steep terrain and steering clear of trigger points such as shallow areas near rocks will be your best bet for avoiding one of these larger and more dangerous slides.
If you thought yesterday was a cold one, just wait for today… We have fallen – literally – off the charts for temperature at many ridgetop locations. Our Friends weather stations are reporting near or below -10F at all locations this morning while lower elevations are slightly warmer in the -5 to +5 range. Temperature will continue to decrease another few degrees over the course of the day. But, skies are clear and the sun will be out! Wind? It was in the bothersome range on the ridgelines yesterday (NW @ 10mph gusting 25mph) and has picked up slightly this morning (predominantly NW @ ~15mph gusting 35mph). Good frostbite weather.
Tomorrow temperatures should bounce back to a more civilized range as winds shift back to the SE bringing clouds and warmer air ahead of a large low pressure system pushing into the Gulf. Snow flurries are in the forecast for Monday night into Tuesday with a better chance for accumulation on Wednesday.
Fitz will issue our next advisory tomorrow morning, January 28th.
|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.