After an action-packed weekend of heavy rain, strong wind and large avalanches, yesterday was a relatively quiet day on Turnagain Pass. With the end of the weekend’s storms came a quick end to the resulting and impressive avalanche cycle. Check out photos of the aftermath on our observation page; including Tim Glassett’s photos from the AKDOT&PF.
A cold front moved through yesterday evening and has begun to freeze and lock-up the snowpack. The very wet snow, which extended to ~2,000′, will likely have a semi-supportable to supportable crust today. As one travels above 2,000′, where the snow was dense and damp, the surface crust should slowly disappear and give way to drier snow and improved riding conditions at the higher elevations.
There is a high uncertainty as to the state of the snowpack following the weekend’s ‘melt-down’ and a shift to colder temperatures freezing it into place. A conservative mind-set will be good in you are headed into the mountains. That said, primary avalanche concerns will be associated with lingering wet snow and deep slab instabilities. Weather today is not expected to add to the avalanche danger as only 1-2″ of new snow is forecast along with light Westerly winds. However, sunlit slopes may see enough warmth to soften Southern aspects and trigger wet sluffs. Primary instabilities include:
In areas that still harbor wet snow, or just a shallow surface re-freeze over punchy saturated snow, large wet slab and wet loose avalanches are still possible. Additonally, sunshine today may increase this likelihood on Southerly slopes. Wet avalanches could be bigger than expected and entrain significant amounts of heavy debris on steep sustained slopes. Steering clear of steep, 40 degree and greater, slopes with soft and saturated snow will be wise.
At elevations above 2,500′ there has been 3-8′ of storm snow from the middle part of April that sits on a variety of old weak layers. Much of the past avalanche activity is suspected to have occurred within these old layers. Now that they are buried so deep in pack, human triggering is not likely, but still something that should be on your radar. Shallow snowpack zones, such as those South of the Pass are the most suspect.
Lingering wind slabs from the weekend’s storms may still be found at the upper elevations. These could be anywhere from 1-5+’ thick.. Again there is a high degree of uncertainty as to how the upper elevations have faired in this respect. Watching for wind textured snow and cracking in the snow around you will be ways of looking for shallow slabs. The deeper wind slabs are more difficult as they likely won’t display signs before releasing.
Photo below is of the very wet and saturated snow from yesterday – which is now freezing into place!
A break in storms came yesterday with mild weather and visibility filtering in and out due to lingering scud clouds. Temperatures were warm, upper 20’s F along the ridgetops and mid 30’s F at 1.000′. Ridgetop winds were light from the Northeast before switching to the West in the evening, bringing much cooler temperatures. Along with the wind shift was a short, 2 hour, burst of precipitation and 2″ of snow fell at the SNOTEL site at 1880′.
Today, cooler temperatures will continue to move through with the Westerly flow direction we are under. There in enough instability to create intermittent snow showers across the region, with accumulations in the 1-3″ range; snow to sea level. Ridgetops winds will be light in the 10-15mph range from the West and temperatures in the teens on the ridges and upper 20’s F at 1,000′.
Wednesday, another round of strong wind with a few inches of snow is on tap, 1-3″. This is a colder storm and flurries should make it to sea level, or close. Ridgetop winds are expected to be in the 20-30mph range from the East and temperatures climbing slightly, to the 20’s F on the ridgelines.
|Temp Avg (F)||Snow (in)||Water (in)||Snow Depth (in)|
|Center Ridge (1880′)||28||2||0.2||74|
|Summit Lake (1400′)||24||3||0.3||16|
|Alyeska Mid (1700′)||30||1||0.2||48|
|Temp Avg (F)||Wind Dir||Wind Avg (mph)||Wind Gust (mph)|
|Seattle Ridge (2400′)||25||n/a||9||25|
|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|
|04/10/21||Turnagain||Observation: north sides||lance breeding|
|04/09/21||Turnagain||Observation: Girdwood to Turnagain Road Observations||W Wagner Forecaster|
|04/05/21||Turnagain||Avalanche: Resort bowl Seattle creek head wall||Clint Kyffin|
|04/04/21||Turnagain||Observation: Center Ridge||Andy Moderow|
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.