There was a skier triggered avalanche observed on Sunburst yesterday. Information is not from party involved but from another group skiing in the area. “A skier then skied down the small bowl just before (west) of where we skied. We didn’t see the slide. But looked up to see him on the bed surface. The crown broke above him and it appeared he was able to self arrest in the bed surface.”
After a few sunny days the next storm is upon us. A couple of inches of snow have fallen, winds are ramping up and temperatures have risen with some weather stations seeing as much as a 30 degree increase. Today that means avalanche danger will be on the rise with variety of storm related avalanche issues. There is plenty of soft snow available for transport and with strong winds in the forecast today into tomorrow, expect wind slab formation on steep leeward slopes and in gully features. As more new snow accumulates with rising temperatures storm slabs will also form in areas out of the wind. Don’t forget the buried weak layers! These could get overloaded and we may see very large avalanches as this storm progresses (see more below in Avalanche Problem 2). If you head out into the mountains today watch for blowing snow, drifting and cracking. As the storm intensifies natural avalanches will become possible. Think about what terrain is above you and avoid avalanche runout zones and terrain traps.
Cornices: With blowing snow and increasing temperatures cornices will grow and could be tender. Natural cornice falls have the potential to trigger avalanches on slopes below.
Loose snow avalanches: At upper elevations loose dry snow avalanches/sluffs are possible in steep protected terrain. On low elevation slopes with heavy wet snow and/or rain possible, watch for wet loose snow avalanches.
For weeks we have been talking about a couple of layers of weak faceted snow and a crust buried in the snowpack. We have seen very large natural and human triggered avalanches fail on these layers and there was a skier triggered avalanche on Sunburst yesterday. We suspect this also failed on facets. Now the concern is that the incoming storm will eventually overload the existing snowpack and result in another widespread avalanche cycle. Today might not be the natural avalanche tipping point but you could still be the trigger if you find the wrong spot. With poor visibility it will be important to choose terrain carefully and avoid runout areas. As the storm intensifies tonight into tomorrow, the potential for avalanches to fail on these deeper layers will increase! We are in an active weather pattern all week. Stay tuned and don’t forget the lurking weak layers!
Yesterday: Skies were mostly clear and sunny with clouds moving in late in the day. Temperatures were in the single digits and teens to low 20°Fs. Winds were mostly calm. Overnight skies became cloudy and temperatures climbed with upper elevations in the teens and mid elevations in the mid to high 20°Fs and sea level weather stations hitting 30°F. An inch of snow fell overnight and easterly winds were in the teens gusting into the 30s.
Today: Cloudy skies and snow with 5-10″ possible and easterly winds 20-30 mph gusting into the 50s. Temperatures will be range with elevation from the low 30°Fs to the high teens. Winds and precipitation intensity will increase overnight and temperatures will climb into the high 20°Fs and 30°Fs. An inch of water/10-15″ of snow is forecasted with rain possible at sea level and maybe as high as 1000′. Precipitation intensity could be heavy at times.
Tomorrow: Heavy snow and rain likely. Winds will remain strong in the morning and slowly diminish later in the day. Temperatures will be in the high 20°Fs to low 40°Fs. Temperatures slightly cool overnight with precipitation shifting to mostly snow. Wednesday precipitation eases off and then another system impacts the area Thursday.
PRECIPITATION 24-hour data (6am – 6am)
|Temp Avg (F)||Snow (in)||Water (in)||Snow Depth (in)|
|Center Ridge (1880′)||17||1||0.1||63|
|Summit Lake (1400′)||12||1||0.1||26|
|Alyeska Mid (1700′)||16||2||0.1||60|
RIDGETOP 24-hour data (6am – 6am)
|Temp Avg (F)||Wind Dir||Wind Avg (mph)||Wind Gust (mph)|
|Seattle Ridge (2400′)||16||SE||7||24|
|02/17/20||Turnagain||Avalanche: Sunburst||CNFAIC Staff|
|02/16/20||Turnagain||Avalanche: Eddies, Sunburst, Cornbiscuit||Alaska Avalanche School L-2|
|02/16/20||Turnagain||Observation: Sunburst||Troy Tempel|
|02/16/20||Turnagain||Observation: Pete’s North||Allen Dahl|
|02/15/20||Turnagain||Observation: Eddies||E. Roberts / R. Van Luit Forecaster|
|02/15/20||Turnagain||Observation: Tincan||Ben Olwell|
|02/15/20||Turnagain||Observation: Wolverine north shoulder||Adrian Beebee|
|02/14/20||Turnagain||Avalanche: Seattle Ridge||Wagner / Van Luit Forecaster|
|02/14/20||Turnagain||Observation: Sunburst and Tincan||Alaska Avalanche School Level 2 class|
|02/13/20||Turnagain||Avalanche: Turnagain – Road Observations||W Wagner 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|
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.