The wet avalanche problem was worse just a few days ago. At this point the cold freezing overnight is creating a stiff crust on the snow surface that takes time for the solar radiation to melt and penetrate into deeper layers. Roller balls and other signs of instability at the surface show up more quickly in powder snow than in our current crust. That being said, sunny skies and warm temperatures can be the trigger for avalanches this afternoon. Travel decisions should be adjusted accordingly to limit exposure to south facing slopes late in the day.
With freezing overnight, the temperatures in the deeper snowpack remain relatively cold. We are not yet reaching the isothermal status where larger and deeper avalanches are expected.
These are pictures of the Goat couloir avalanche from Tuesday, a great example of the worst case scenario right now. This appears to be a very large cornice failure, which triggered a slab below and to the side of the cornice. The resulting avalanche traveled far for this path.
Cornices will become less stable in the afternoon as the sun heats them up and weakens their overhanging structure.
Several days of clear skies and strong temperature swings between day and night are creating a melt/freeze cycle on the snow surface. Temperatures last night dipped to the mid teens at 4000 feet elevation after reaching above freezing during the day. At sea level peak daytime temperatures hit the low 40s in some areas. Wind has been light, and we haven’t had any precipitation in several days.
Today’s weather looks like more of the same, but a change is expected tonight. Snowfall is in the forecast for the weekend and into next week.
Fitz will issue the next advisory Saturday, April 6th.
|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.