The primary concern today is still the deep slab, which is becoming more stable over time. We haven’t had reports of deep slab avalanches since Monday when the last storm system ended. The snowpack is showing evidence of strengthening, but a number of tests consistently still show a low probability of initiating a large avalanche.
This kind of deep slab problem needs to earn our trust. We have growing confidence, but only to a certain point. The consequences of causing a full depth avalanche still deserve our respect and some alteration in our terrain choices. Areas with thinner snow cover are more suspect, and steep rocky terrain may hold the trigger points that could activate a large avalanche.
Now that the deep weak layer has been dormant for a few days we can expect a low possibility of triggering it. A new significant snow load (which is in the weather forecast for tonight) will increase the chances of deep slab activity as additional stress gets added to the weak foundation (see picture below).
The small amount of snow predicted to fall this afternoon will build wind slabs at higher elevations. Based on the timing of this storm it looks like this problem will be minor today, but may build into a significant problem tomorrow.
A blizzard watch is in effect for Girdwood, Seward, and Whittier starting this evening. It appears that this will not have a major effect on the daylight hours today, but it may cause a bump in the avalanche danger by tomorrow. We can expect increasing wind and up to 5 inches of snow by this evening.
If you are wondering how the mountains are doing for snow this year check out the graph below. Our snow depth is slightly above average, and the Snow Water Content measured at 1880 feet at Turnagain Pass (below) is just barely below average.
|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: 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.