For most folks that have been in the backcountry lately it is hard not to notice the collapsing in the snowpack. Other than a few avalanches in the past week, this has been our prominent ‘obvious clue’ as to the weak snow lying 12-18” below the surface. If you look at the two observations sent in yesterday, both highlight collapsing (or whoomphing). You can see them HERE and HERE. Other red flags are found by digging in the snow. However, a collapse trumps all and essentially means that if a slope is steep enough chances are it will avalanche.
With weak layers in the pack that are hard to assess from the surface, keeping with safe travel practices will help to hedge your bets if riding/skiing on steep slopes. These include watching your partners, exposing only one person at a time and having an escape route planned if the slope avalanches.
Below is a cross section of the snowpack at 3,200′. You can see a vertical crack in the ‘slab’ and the weak snow (lighter colored) below a crust. This if from a snow pit on Magnum, SW facing. – more details and video HERE.
We received 2-3″ of snow from Friday night that was blown into drifts on the ridgelines. Cornices grew a bit with this event and some small to medium natural cornice failures were seen yesterday. This snow has shown signs of bonding well with the surface and is now part of the ‘slab’ mentioned above.
Below treeline the slab is losing its cohesion and the pack is unsupportable. Though there is some localized collapsing in the alders, triggering an avalanche is unlikely.
During the past 24-hours we have seen a slight warm up above treeline (20-25deg) and a slight cool down at sea level (upper 30's to low 20'sF) due to minimal cloud cover producing a weak inversion. Winds have been light from the Southeast and have switched to the Northwest overnight. We only picked up ~3 € above treeline with Friday night's snow event.
Today we will see a weak disturbance move over us from the Gulf bringing mostly cloudy skies and continued warm temperatures. Ridgetops will be in the mid 20'sF with winds shifting back to the Southeast and picking up through the day to the 20mph range by the evening hours.
There is a possibility for precip on Tuesday into Wednesday as a warm low pressure system moves in from the South. How much will depend on the track this low takes but it is fairly warm with rain at sea level likely.
|05/18/21||Turnagain||Observation: Tincan Ridge||Joe Kurtak|
|04/30/21||Turnagain||Observation: Sunburst||W Wagner Forecaster|
|04/27/21||Turnagain||Observation: Tincan Ridge||Joe Kurtak|
|04/26/21||Turnagain||Observation: Magnum||Creighton/ Hoople|
|04/25/21||Turnagain||Observation: Sunburst||Nick D'Alessio|
|04/24/21||Turnagain||Observation: Airplane obs||Johnston-Bloom / DiJulia /Hilliard Forecaster|
|04/24/21||Turnagain||Observation: Corn biscuit||Heather Johnson|
|04/23/21||Turnagain||Avalanche: Lynx Ck Drainage||W Wagner Forecaster|
|04/23/21||Turnagain||Avalanche: Sunburst||Eeva Latosuo|
|04/23/21||Turnagain||Observation: Center Ridge Turnagain pass||Joe Kurtak|
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.