The primary concern today is a one-week old slab (1 – 3’ deep) sitting on a layer of buried surface hoar. Buried surface hoar has been found over the past week throughout Turnagain Pass and Summit Lake above 2000’ on all aspects. This particular combination of weak layer plus slab is known to linger for long periods of time and explains why we are still getting some moderate to hard results in our test pits when we isolate the weak layer. No new signs of obvious instability have been reported since the Sunburst avalanche that buried one skier on December 18th. This leads us to believe that the weak layer is adjusting to its new load and the overall stability of the snowpack is gradually improving.
The weather forecast today is calling for 3-5″ of new snow throughout the day with moderate winds. This new load will contribute to our primary concern by placing additional stress on the weak layer.
It’s important to realize a MODERATE rating refers mainly to the likelihood of initiating an avalanche and does not take consequences into consideration. If you were to find just the right trigger point to initiate an avalanche it could propagate across the entire slope, making escape difficult at best. Because of this we are on the higher risk side of the moderate scale.
Persistent slabs are most likely to be triggered on steep slopes in thinner areas of the snowpack. We are advising backcountry users to be smart about terrain choices and to think about the consequences before deciding to ski a steep slope. Take the time to evaluate the terrain and avoid steep slopes with convex rollovers or shallow areas around rocks.
Ridgetop winds are expected to be moderate with gusts into the mid twenties today. We have an existing 5 inches of low density snow available for transport and are expected to recieve another 3-5″ throughout the day. This is just enough wind and snow to form isolated wind slabs up to 8″ deep on leeward aspects. Terrain features such as ridges, gullies and convex rollovers will be the most likely places to encounter these newly formed pockets of slab. These slabs are expected to be small and isolated, but if caught off guard could be enough to knock you off your feet. Pay attention to the consequences below and look for obvious signs like shooting cracks, hollow sounds, or smooth pillowy looking features.
Yesterday skies were clear; winds were calm, and temperatures were in the 20’s F.
Overnight winds remained calm, temperatures dipped into the teens, and no precipitation was recorded.
Today temperatures are expected to remain in the high 20’s F at 1,000′ and 3-5 € of snow is forecasted for today. Ridgetop winds are expected to increase to 15-25 mph out of the East.
Another 3-6 € of snow is expected tonight and could continue through Christmas day. Temperatures are expected to stay in the 20’s F with highs in the low 30’s F near sea level. Winds are expected to remain moderate throughout the evening.
|Temp Avg (F)||Snow (in)||Water (in)||Snow Depth (in)|
|Center Ridge (1880′)||24||0||0||29|
|Summit Lake (1400′)||15||0||0||4|
|Alyeska Mid (1700′)||25||0||0||21|
|Temp Avg (F)||Wind Dir||Wind Avg (mph)||Wind Gust (mph)|
|Seattle Ridge (2400′)||22||N/A||N/A||N/A|
|04/21/21||Turnagain||Observation: Sunburst||Schauer/ Behney Forecaster|
|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|
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.