A snowboarder triggered a small wind slab in Juniors and was caught and carried with no burial or injury. They did deploy their airbag but it did not fully inflate.
|Signal Word||Size (D scale)||Simple Descriptor|
|Small||1||Unlikely to bury a person|
|Large||2||Can bury a person|
|Very Large||3||Can destroy a house|
|Historic||4 & 5||Can destroy part or all of a village|
Yesterday many people were out in forecast area enjoying the snow and stability. Observers did note a few wind slab pockets and wind effect in exposed terrain. Last night there was a brief bump in the ridgetop winds. Today there is still plenty of soft snow available for transport. With additional light snow in the forecast and winds building this afternoon, it will be important to pay attention to changing conditions. Wind slabs up to a foot thick will be possible in steep leeward terrain. Look for blowing snow, shooting cracks and stiff wind affected snow. Even a small wind slab avalanche in steep terrain can take a skier or boarder for an unpleasant ride. As always, give cornices plenty of space, they often break back farther than you would expect.
In addition, don’t forget loose snow avalanches, i.e. sluffing, in steep wind protected terrain. Observers commented on these being big enough push folks around and it will be possible to see more of the same today.
The big news is the incoming storm. As noted above in the Bottom Line, the NWS has issued a High Wind Warning and a Blizzard Warning starting tonight. Today is not the day to get stuck out after dark, especially on the shortest day of the year. Conditions are expected to deteriorate rapidly.
We know there is weak snow at the base of the snowpack throughout the advisory area, which has been a concern above 2500′ where the stout crust December 1st crust disappears. However, the facet layer (sugar snow) is variable in grain size, layer thickness and has shown signs of gaining strength. With no avalanche activity failing at this layer in over two weeks, very few signs indicating instability, and no significant loading in over a week, it has become very unlikely to trigger an avalanche deep in the snowpack. This layer remains a bit more concerning in areas with thinner snowpack such as Crow Pass, and as you head south from Turnagain Pass (Lynx Creek, Silvertip) towards Summit Lake. This type of avalanche problem is tricky. Deeply buried weak layers can often lay dormant for weeks or longer without showing any signs of activity before somebody finds just the wrong spot to trigger one. If you want to avoid the chance of this type of avalanche entirely, you can stay off steep, rocky, slopes over 35 degrees.
With a heavy loading event in the forecast tonight through tomorrow, we will be watching to see if this layer gets woken up from it’s slumber…
Yesterday: Skies were partly cloudy with light southerly winds and temperatures in the teens to mid 20°Fs. Overnight skies remained partly cloudy, ridgetop winds were westerly, 5-15 mph with gusts into the 30s. Temperatures were in the low teens to low 20°Fs. There was a trace of snow overnight in Girdwood.
Today: Happy Solstice! 5.5 hrs of daylight today. Skies will be mostly cloudy with snow showers starting mid-day, 1-5″ forecast. Light southerly winds this morning becoming easterly this afternoon, 10-20 mph gusting into the 30s. Temperatures will be in the teens in the Alpine and the low 30°Fs at sea level. Overnight easterly winds are forecast to increase to 40 to 65 mph with gusts to 90 mph expected. Snow is expected to be heavy, falling 2″ per hour with over 2′ by the morning. Temperatures will be in the 20°Fs.
Tomorrow: Heavy snow and then heavy rain expected. Rain/snowline is still TBD, with another 1-2′ of snow forecast. Winds will remain very strong until mid day and then ease off a little by late afternoon. Temperatures will be in the 40°Fs at sea level and the high 20°Fs at ridgetops. Heavy rain and snow continue overnight, 4-6″ of total water from the storm is expected by Wednesday morning. The weather pattern remains active through the holiday weekend.
PRECIPITATION 24-hour data (6am – 6am)
|Temp Avg (F)||Snow (in)||Water (in)||Snow Depth (in)|
|Center Ridge (1880′)||22||0||0||59|
|Summit Lake (1400′)||15||0||0||27|
|Alyeska Mid (1700′)||21||trace||0||59|
RIDGETOP 24-hour data (6am – 6am)
|Temp Avg (F)||Wind Dir||Wind Avg (mph)||Wind Gust (mph)|
|Seattle Ridge (2400′)||16||SE||5||15|
|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|
|04/15/21||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|
|04/03/21||Turnagain||Observation: Repeat Offender – Seattle Ridge||Troy Tempel|
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.