Yesterday there was enough visibility to look around and see the evidence of a natural avalanche cycle in the advisory area. This confirmed that the new snow, strong winds and rain overloaded the weak layer of buried surface hoar and near surface facets. The connected slab avalanches on Eddies were the most notable in Turnagain Pass. The crowns extended along terrain features. Today any additional snow will add weight to the storm slab over the weak layer. Surface hoar and near surface facets are buried now by 1-3′ of snow. Slopes that didn’t avalanche naturally could now be teetering on the brink of failure just waiting for a human trigger. Conservative decision-making is essential today. Slopes harboring surface hoar and near surface facets may also be triggered remotely.
There really is a smorgasbord or buffet of issues to consider if you decide to venture out today. Strong winds have loaded leeward aspects and potentially created winds slabs as well as growing cornices. At lower elevations if there is still saturated snow wet avalanches are possible in steep terrain. As temperatures cool these will be less likely and the crust that was noted to 2300′ may have grown stouter and more supportable. The “railroad skiing”/ breakable crust will hopefully improve. In addition, pay attention to whether or not the new snow that falls to today bonds to the crust.
Recent natural avalanches on Eddies.
The buried surface hoar is the suspected weak layer and our layer of concern.
In the alpine, above 3,000’, the storms over the past few days have added additional load to slopes that already have a hard slab, 3-5+ feet thick, is sitting on top of weak sugary snow (basal facets) near the ground. We have been talking about this for weeks now. At these elevations, human triggered, large and dangerous deep slab avalanches ARE still possible. This is a high consequence avalanche problem that is impossible to outsmart and can take a long time to heal. Keep this in mind as improving visibility in the next few days may allow for travel to the Alpine. It is really important to remember that triggering an avalanche in the upper layers of the snowpack on may then initiate a deep slab avalanche. Cautious route-finding is essential. This includes thinking about the remote trigger potential from below.
Yesterday was mostly overcast with a few breaks in the cloud cover. There were rain and snow showers on and off throughout the day. Rain/snowline went as high as 2300′ in the morning and then crept back down to around 1500′. Temperatures were in the mid to high 20Fs in the alpine, 30Fs at mid-elevations and 40Fs at sea level. Overnight the temperatures cooled a bit. Winds were easterly 15-25 mph gusting into the 50s, slowing down in the evening.
Today will be mostly cloudy with rain and snow showers. Rain/snowline is forecasted to be around 800′. 1-5″ of snow, .25 water is possible throughout the day. Temperatures will be in the mid 30Fs to mid 20Fs. Winds will be light and variable. There is a chance of continued snow showers into the evening as temperatures cool into the teens. Skies will clear overnight.
Thursday and Friday look to be clear and sunny with calm winds and temperatures in the 20Fs. There is snow in the forecast for the weekend but the timing, amount and temperatures are still TBD. Stay tuned and keep thinking cold powder thoughts!
*Seattle Ridge anemometer is rimed.
|Temp Avg (F)||Snow (in)||Water (in)||Snow Depth (in)|
|Center Ridge (1880′)||35||rain||.2||46|
|Summit Lake (1400′)||33||rain||.2||14|
|Alyeska Mid (1700′)||34||.5||1.5||36|
|Temp Avg (F)||Wind Dir||Wind Avg (mph)||Wind Gust (mph)|
|Seattle Ridge (2400′)||28||*n/a||*n/a||*n/a|
|12/06/19||Turnagain||Avalanche: Sunburst||Billy Finley|
|12/04/19||Turnagain||Observation: Sunburst||A.Johnston-Bloom/ W.Wagner/ R.Van Luit Forecaster|
|12/03/19||Turnagain||Observation: Hippy Bowl||Nick Langowski|
|12/01/19||Turnagain||Observation: Tincan, All elevations||Eric Roberts|
|12/01/19||Turnagain||Observation: Tincan||Andy Moderow|
|11/30/19||Turnagain||Observation: Tincan Treeline Plateau/ Common Bowl/ Ridge||Eric Roberts|
|11/29/19||Turnagain||Observation: Sunburst Ob #2||Aleph Johnston-Bloom Forecaster|
|11/29/19||Turnagain||Observation: Sunburst Ob #1||Aleph Johnston-Bloom Forecaster|
|11/27/19||Turnagain||Observation: Tincan||Aleph Johnston-Bloom Forecaster|
|11/25/19||Turnagain||Observation: Sunnyside||Graham Predeger 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: firstname.lastname@example.org
|Area||Status||Weather & Riding Conditions|
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