Turnagain Pass RSS

ARCHIVED - Forecasts expire after 24 hours.
Thu, December 1st, 2016 - 7:00AM
Fri, December 2nd, 2016 - 7:00AM
Aleph Johnston-Bloom
Avalanche risk The Bottom Line

The avalanche danger is CONSIDERABLE.  New snow and sustained winds have loaded a weak snowpack.  Triggering a slab 1 – 2 feet thick is likely. Cautious routefinding and conservative decision-making will be essential.  

***Observations from the Summit Lake area on the Kenai are showing a similar snowpack. Weekly summaries will begin tomorrow, December 2nd.  

Special Announcements

There is a Motorized Closure order in effect for both the Seward and Glacier Ranger Districts beginning today, Dec 1st due to insufficient snow cover. We will monitor conditions daily.  

Thu, December 1st, 2016
Above 2,500'
3 - Considerable
Avalanche risk
3 - Considerable
Avalanche risk
Below Treeline
Below 1,000'
0 - No Rating
Avalanche risk
0 - No Rating
1 - Low
2 - Moderate
3 - Considerable
4 - High
5 - Extreme
Avalanche risk Avalanche risk Avalanche risk Avalanche risk Avalanche risk
Travel Advice Generally safe avalanche conditions. Watch for unstable snow on isolated terrain features. Heightened avalanche conditions on specific terrain features. Evaluate snow and terrain carefully; identify features of concern. Dangerous avalanche conditions. Careful snowpack evaluation, cautious route-finding, and conservative decision-making essential. Very dangerous avalanche conditions. Travel in avalanche terrain not recommended. Extraordinarily dangerous avalanche conditions. Avoid all avalanche terrain.
Likelihood of Avalanches Natural and human-triggered avalanches unlikely. Natural avalanches unlikely; human-triggered avalanches possible. Natural avalanches possible; human-triggered avalanches likely. Natural avalanches likely; human-triggered avalanches very likely. Natural and human-triggered avalanches certain.
Avalanche Size and Distribution Small avalanches in isolated areas or extreme terrain. Small avalanches in specific areas; or large avalanches in isolated areas. Small avalanches in many areas; or large avalanches in specific areas; or very large avalanches in isolated areas. Large avalanches in many areas; or very large avalanches in specific areas. Very large avalanches in many areas.
Avalanche Problem 1
  • Persistent Slabs
    Persistent Slabs
Persistent Slabs
Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.
More info at Avalanche.org

We received the lower end of forecasted snow amounts with only 5-7 inches falling across the advisory area. This might not seem significant but there are few important factors to keep in mind. First this fell on weak surface snow, second it came in with easterly winds blowing in the 20s and gusting as high as 60mph on Sunburst, third there was already soft snow available to transport and finally the temperatures were steadily rising throughout the storm so the snow will be upside down. Colder snow will be under warmer heavier snow. Then put this all on top of the surface hoar that has been the culprit in all of the avalanche activity in the last two weeks. This surface hoar sits 1-2 ft below the surface and has shown that it still has the potential to avalanche. It now has additional load on top of it and may have a more connected slab due to wind-loaded snow.  Some slopes have slid on this layer and some haven’t. This combination warrants caution. It may be triggered remotely and may let you get out onto the slab before it breaks. The new snow and wind might have been the tipping point or your weight might be when you get onto the slope. 

Today it will be important to look for recent avalanches, cracking and collapsing (whumpfing). In addition look for wind deposition, wind slabs, newly formed cornices and places where you feel stiffer snow over soft snow. Keep slope angles low and pay attention to what is above and below you. Remember the buried surface hoar when you are making your slope decisions. 

Buried surface hoar picture taken November 19th. Photo: Wendy Wagner

This photo was taken yesterday, November 30th on Manitoba and the same layer is still visibly intact and still showed the potential to avalanche in stability tests. 


Avalanche Problem 2
  • Storm Slabs
    Storm Slabs
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.
More info at Avalanche.org

The new snow last night fell onto weak surface snow, came in with wind and with a rise in temperature.  Storm slabs may be easy to trigger even at lower elevations. Investigate whether the new snow is bonding to the old snow surfaces. Pay attention to cracking and collapsing. 

Additional Concern
  • Glide Avalanches
    Glide Avalanches
Glide Avalanches
Glide Avalanches are the release of the entire snow cover as a result of gliding over the ground. Glide avalanches can be composed of wet, moist, or almost entirely dry snow. They typically occur in very specific paths, where the slope is steep enough and the ground surface is relatively smooth. They are often proceeded by full depth cracks (glide cracks), though the time between the appearance of a crack and an avalanche can vary between seconds and months. Glide avalanches are unlikely to be triggered by a person, are nearly impossible to forecast, and thus pose a hazard that is extremely difficult to manage.
More info at Avalanche.org

Watch for glide cracks and remember to limit time under these, there have been a handful that released last week. *Several cracks have been opening in popular terrain like Tincan’s Common bowl and the SW face of Sunburst. These may be hard to see with new snow.


Thu, December 1st, 2016

Yesterday was overcast with light snow falling during the day. In the late afternoon snowfall picked up with a period of heavy snow from 3pm-7pm. Temperatures steadily rose throughout the day going from single digits into the high 20Fs. Sustained easterly winds blew 20-30 mph with gusting into the 60s.  

Today will be mostly cloudy with snow showers. 0-3′” of new snow. East winds will be light 5-15mph and temperatures will be in the high 20Fs. Tonight the chance of snow showers continues with another 0-3″ possible. Winds shift to the north and temperatures drop into the low 20s and teens.  

Tomorrow will be mostly cloudy with light north winds and temperatures in the low 20s. There is a cooling trend into the weekend and a chance for more snow early next week.  

PRECIPITATION 24-hour data (6am – 6am)

  Temp Avg (F) Snow (in) Water (in) Snow Depth (in)
Center Ridge (1880′) 21   5   .5    22
Summit Lake (1400′) 20   3   .3  4
Alyeska Mid (1700′) 22 7 .7    11

RIDGETOP 24-hour data (6am – 6am)

  Temp Avg (F) Wind Dir Wind Avg (mph) Wind Gust (mph)
Sunburst (3812′) 16   ENE    30  63
Seattle Ridge (2400′)  18 ESE   17    41
Recent Observations for Turnagain Pass
Date Region Location
05/13/24 Turnagain Observation: Eddie’s, Sunburst, Seattle, Cornbiscuit, Pete’s South
05/13/24 Turnagain Observation: Turnagain Pass non-motorized side
05/12/24 Turnagain Observation: Warm up Bowl
05/07/24 Turnagain Observation: Turnagain Pass Wet Slabs
04/29/24 Turnagain Avalanche: Turnagain aerial obs
04/27/24 Turnagain Observation: Johnson Pass
04/23/24 Turnagain Observation: Turnagain Sunny Side
04/21/24 Turnagain Observation: Bertha Creek
04/20/24 Turnagain Avalanche: Spokane Creek
04/16/24 Turnagain Observation: Cornbiscuit
Riding Areas

The riding areas page has moved. Please click here & update your bookmarks.

Subscribe to Turnagain Pass
Avalanche Forecast by Email

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.