Strong winds accompanied with new snow have combined to create dense slabs 2-3′ in depth in many areas. With sustained winds averaging well over 30mph across the forecast area, expect to find wind slabs on a wide variety of aspects especially in the upper elevations. Strong winds tend to deposit snow in the form of wind slabs further down slopes than normal. While bonding of the new snow to the old snow is generally good, rapid loading caused by high winds is enough of a factor to create unstable conditions. Pay attention to the makeup of the snow your are traveling on; if it feels punchy or sounds hollow and you’re in steep terrain, back off.
Storm snow unaffected by wind will be more of a concern around the Girdwood Valley, where snowfall amounts are closer to a foot. Less snow fell on Turnagain Pass and in the Placer Valley. In general this storm started out windy and warm which allows for good bonding between the old snow surface and this newest slab. Slopes with more than 10 inches of new snow should be treated as suspect today.
Yesterday my partner and I found a weak layer of snow below a crust to be somewhat reactive in tests. This interface was about 30″ below the surface and could pose a problem at mid elevations. This is not a widespread problem but is worth keeping in mind as new snow avalanches have some potential to step down to older buried weak layers.
Cornices have gained in mass in the past 24 hours. Natural cornice breaks are possible today. Give cornices plenty of room today, as they will be very sensitive to human triggers. Cornices have the potential to trigger slab avalanches after falling and impacting slopes. We have seen cornices to be a problem lately during and after storms.
In the past 24 hours strong winds out of the East have averaged 43 mph with gusts as high as 110mph at the Sunburst station (3,880′). The peak intensity of winds occurred around 8pm last night. Winds are still blowing in the 30mph range at ridgetops this morning, which is plenty of wind to transport snow. Snowfall amounts have varied across the forecast zone with the Girdwood Valley picking up to 14″ of new snow with 1.4″ of water, Turnagain Pass getting 8″ of snow with .6″ of water and Grandview picking up a rain snow mix with a few inches of snow and .2″ of water. Freezing levels have hovered around the 500-1,000′ level.
Today expect another 3-6″ of new snow and winds to continue to blow in the 30 mph range out of the Southeast with gusts to 50mph. Temps at 1,000 will be around 33 degrees F.
Light snowfall will continue tonight and taper off by tomorrow. Lingering clouds and precip will then stick around through tomorrow prior to high pressure setting in by Sunday.
Kevin will issue the next advisory tomorrow morning, March 9th.
|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: 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.