The weak snow that is buried 12-18” deep in our snowpack remains our primary concern. The likelihood for triggering a slab avalanche that breaks in this older weak snow has been decreasing the last several days but the possibility does remain.
We have a small shot of snow expected today (1-3” forecast) with moderate to strong wind. Slopes where the wind is depositing snow will add stress to these buried weak layers and increase the likelihood of triggering one of these old slabs. However, the ‘real’ snow and wind event is expected overnight tonight through tomorrow where a foot or more of new snow will have the potential to overload the weak layers. We could see large and unmanageable avalanches 2-3+’ deep by tomorrow if this storm does verify.
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.
Easterly winds will start picking up through the day to the moderate range on the ridgelines with gale force winds expected for tonight. Though there is limited snow to transport at the moment, we do have 1-3” of snow forecast to fall before 6pm. Watch for wind drifts and shallow slabs to start forming through the day. These should be confined to above treeline slopes and exposed rollovers.
We have had a mild past 24-hours with temperatures in the mid 20’s F above sea level, light easterly winds at ridge tops and overcast skies.
Today a change is in store as a large area of low pressure heads our way from the South. We should see East winds pick up by the afternoon to the 30-40mph range on the ridgelines with 70-80mph by late tonight. Temperatures should be around 20F above treeline and near 32 at sea level. Snow accumulation of 1-3 € is expected with a snow/rain mix at sea level.
By tomorrow evening we are looking a total snowfall of 12-16 € (possibly more). The models are saying around 1.5 € of water equivalent from this afternoon through Wednesday night. It does look like we could finally get a decent shot of snow.
Some December stats below:
We end 2013 with a SWE that is only 15% of average for December. We also made the podium with this December being the 3rd driest since 1983. Numbers below are from the Turnagain Pass SNOTEL Station (1880′).
Top 5 lowest December SWE from 1983 till 2013:
1st 1984 €“ 0.5 €
2nd 2011 €“ 1.3 €
3rd 2014 €“ 2.5 € (plus whatever might fall before midnight tonight)
4th 1985 €“ 3.1 €
5th 2009 €“ 4.2 €
Average December SWE is 16.2 €
Dec 31 2013, today, snow depth 22 €
Average for past 10 years is 64 € (Data only goes back to 2004)
*The above numbers were calculated with SNOTEL data from the NRCS.
|01/18/21||Turnagain||Observation: Turnagain Pass Road Obs.||A Schauer|
|01/16/21||Turnagain||Avalanche: Tincan Trees||A Schauer Forecaster|
|01/15/21||Turnagain||Observation: Sunburst||Schauer/ Wunnicke Forecaster|
|01/13/21||Turnagain||Observation: Tincan||Johnston-Bloom / Moderow Forecaster|
|01/13/21||Turnagain||Observation: Center Ridge Meadows||Alaska Avalanche School Rec Level 1 Roberts|
|01/12/21||Turnagain||Avalanche: Seattle Ridge/Center Ridge||A Schauer Forecaster|
|01/11/21||Turnagain||Observation: Tincan Trees||Schauer/ Roberts Forecaster|
|01/10/21||Turnagain||Observation: Center Ridge Meadows||Alaska Avalanche School Pro 1 Course Latosuo|
|01/10/21||Turnagain||Avalanche: Tincan trees||Anonymous|
|01/09/21||Turnagain||Observation: Johnson Pass||Anonymous|
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.