Winds over the last 24 hours have been strong enough to move around snow to create sensitive slabs. Yesterday my partner and I observed these slabs starting to build. Other parties reported similar conditions along and near ridge crests and on leeward slopes. These slabs will be most likely to propagate and pick up speed on steep south facing upper elevation starting zones and above cross loaded gullies. If you notice shooting cracks or the snow below your feet or sled feels hollow and you happen to be in steep terrain, back off before you’re moving downhill with the slab. Warmer temps and continued high winds will help to make these slabs be “upside down” and release with ease.
While snowfall amounts have been lower than what was forecasted yesterday, there is still enough loose snow in non wind affected areas to warrant attention. Volume of these sluffs should be in the low to medium range. Volume will increase as more snow accumulates through the day. Sluffs will release more easily as temps climb. On steep south facing terrain crusts will allow the snow to move more quickly. These avalanches will be manageable on their own but have the potential to carry people into gullies & trees, and over cliff bands. Choosing terrain that gives you options for escape will be important in dealing with this problem today.
Additional Concern—Cornice Fall
The winds of the past day have also helped to build the size of cornices. Steer clear of these behemoths as they can do significant damage. The largest avalanches that have occurred in the month of March have been the result of cornices dropping.
In the past 24 hours the Turnagain Pass SNOTEL has picked up 6″ of new snow with .5″ of water. Winds at the Seattle Ridge weather station at 2,400′ have averaged 30mph out of the SE with gusts to 59mph. Temperatures have averaged 16.5 degrees F at this location. Temperatures have been on the rise since the early morning hours and are currently in the low 20s F.
Today expect continued intermittent snowfall, with 4-7″ of accumulation possible. Winds at ridge tops will average 35-40mph out of the SE with gusts over 50 mph. Temperatures at 1,000′ will be in the low to mid 30 F range.
The extended outlook calls for a continuation of unsettled weather going into the weekend with snowfall amounts remaining relatively light.
Kevin will issue the next advisory tomorrow morning, March 30th.
|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|
|01/19/21||Turnagain||Avalanche: Seattle Ridge||CNFAIC Staff|
|01/19/21||Turnagain||Avalanche: Tincan 2900′ SW aspect below Hippy Bowl.||Kris Marshall|
|01/18/21||Turnagain||Observation: Turnagain Pass Road Obs.||A Schauer Forecaster|
|01/16/21||Turnagain||Avalanche: Tincan Trees||A Schauer 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.