High pressure and mild temperatures continue to dominate much of our State. This ‘lack of weather’ over the last week and a half has contributed to a stabilizing trend in the snowpack that has been afforded ample time to adjust to our most recent winter storm (March 10-14th).
Specific hazards one may experience when travelling into the backcountry today include threatening cornices, wet loose avalanches late in the day, shallow wind slabs or an unlikely but very dangerous persistent slab. Furthermore, surface conditions are quite variable throughout the backcountry right now. Read here and here for a couple different accounts of a heinous fall (but positive outcome) a snowboarder took on Sunday in the Chugach range.
Perhaps the most unpredictable problem today, we’ve seen evidence in the last week of natural cornice failure that have subsequently triggered slab avalanches. This is the type of large trigger likely needed to wake up a persistent slab that could result in a large and destructive avalanche. Your best mitigation tactic for cornices is to recognize them and limit exposure on top of or underneath these bulbous snow formations, particularly late in the day when solar input is greatest.
Wet loose avalanches:
We saw evidence yesterday on the sunny side of Turnagain Pass where wet-loose avalanches or point-releases initiated and ran several hundred feet. Though not a huge problem on their own, this is the type of small slide that can get you into big trouble if above a terrain trap or in complex, “no-fall” terrain. It’ll be best to avoid steep, southerly aspects late in the day once you begin to notice the snow surface will no longer support your weight off your skis or sled.
Wind slab and persistent slabs:
Older wind slabs from last week may still be lurking in untested terrain today. With people pushing further out into the periphery and skiing bigger, more committing lines over the last week the possibility of triggering an older, stiff wind slab exists.
A note on persistent slabs: The nature of this avalanche problem is persistent. Though unlikely to trigger today, we know that weak snow layers do exist 2-5’ deep and a resulting persistent slab avalanche would likely be un-survivable. To mitigate this problem, follow safe backcountry travel protocol that includes wearing and knowing how to use rescue gear and exposing only one person at a time on a given slope.
Clear blue skies, light wind and warming temperatures yet again dominated our environment if you were so lucky to venture outside yesterday. Ridgetop winds were light out of the east and temperatures averaged in the mid-20’s at these upper elevations. At sea level locations and in valley bottoms cold air-pooled to create a decent temperature inversion yesterday morning.
Today looks to be a similar set-up as yesterday with the rising sun breaking up that inverted layer (8 deg at Granite campground this morning and 24 deg at Sunburst weather station) by mid-day and temperatures steadily climbing into the low 40’s at 1,000′. Winds have shifted slightly to a westerly direction but look to be light and variable all day.
It looks like this stubborn blocking high pressure is here to stay well into next week as clear skies will continue to support warmer than normal high temperatures and below normal lows overnight.
|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.