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Fri, April 1st, 2016 - 7:00AM
Sat, April 2nd, 2016 - 7:00AM
Aleph Johnston-Bloom
Avalanche risk The Bottom Line

The avalanche danger is MODERATE  today due to above freezing temperatures, rain and an active glide avalanche cycle. Human triggered wet loose avalanches are possible in steep mid-elevation terrain (1000′-2500′). Triggering a fresh wind slab or cornice fall is possible in the Alpine.  Avoid being under the runout of glide cracks.

Summer use trails with avalanche terrain above should be avoided due to the threat of natural avalanche activity from above. Byron trail in Portage Valley is not recommended and the Turnagain Arm Trail between Bird and Girdwood remains  CLOSED for the winter.

*If you are headed to the Summit Lake area don’t forget to check  Summit Lake Summary.  

Special Announcements

CNFAIC is going to Arctic Man for the fifth year in a row! We are excited be there all week and to offer two FREE companion rescue workshops. Click  HERE  for more information. We hope to see you there! Stop by the blue trailer and practice in the beacon park!  Don’t forget your beacon, shovel and probe!

Fri, April 1st, 2016
Above 2,500'
2 - Moderate
Avalanche risk
2 - Moderate
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
  • Wet Loose
    Wet Loose
Wet Loose
Wet Loose avalanches are the release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry Avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.
More info at Avalanche.org

Record high temperatures were seen around the state yesterday and advisory area saw the warmest temperatures of the season to date.

Sunburst, 3800′: 41F 

Seattle Ridge, 2400′: 44F

Center Ridge, 1880′: 57F

Summit Lake 1400′: 57F

Alyeska mid mountain, 1700′: 48F

Clear skies on Tuesday night that allowed for a surface freeze and winds throughout the day helped keep the natural wet loose activity to minimum despite the warm air temperatures. The building daytime cloud cover across the region also added to the variability of surface warming. In sunny areas there was obvious free water in the snowpack as the day heated up. Last night cloudy skies and rain falling (Center Ridge Snotel recorded an inch of water) will keep the mid-elevation snowpack prime for human triggered wet loose activity on steep slopes. Watch for ski and snowmachine penetration and get off slopes if you are sinking in. Remember once wet snow gets moving it often entrains more snow quickly and can be hard to escape. Yesterday there was a report of skier triggered wet loose avalanche in the Summit area on Butch mountain on a west aspect in the afternoon.

Turnagain Pass from the Center Ridge parking lot. Note the surface reflecting in the sun and the large glide crack on the N face of Cornbiscuit.

Avalanche Problem 2
  • 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

No glide avalanches were reported yesterday on the warmest day we have had this season. What???……. April Fools! Of course there were glide avalanches reported and observed yesterday. A number of new glide avalanches were observed on Seattle Ridge, in Summit Lake and the Girdwood Valley. We are now trying to track areas to see if glides are releasing in spots without pre-existing cracks. If this is the case steering clear of steep terrain in the mid-elevation band around (not just below) glide cracks may also be advised. Visibility may be limited today and make it harder to see where you are in terrain. We can’t stress this message enough: Avoid being under the runout of glide cracks. Avoid being under the runout of glide cracks. Avoid being under the runout of glide cracks. 

Glide avalanche on Seattle Ridge that released sometime between 9 am and 1 pm.

 I am going to include Heather’s photo from Wednesday again. I think the glide avalanche hazard on the Seattle Ridge up-track is particularly dangerous. 

Additional Concern
  • Cornice
Cornice Fall is the release of an overhanging mass of snow that forms as the wind moves snow over a sharp terrain feature, such as a ridge, and deposits snow on the downwind (leeward) side. Cornices range in size from small wind drifts of soft snow to large overhangs of hard snow that are 30 feet (10 meters) or taller. They can break off the terrain suddenly and pull back onto the ridge top and catch people by surprise even on the flat ground above the slope. Even small cornices can have enough mass to be destructive and deadly. Cornice Fall can entrain loose surface snow or trigger slab avalanches.
More info at Avalanche.org

Cornices remain extremely large and perched along many ridgelines.  We haven’t seen an active day of widespread cornice failure yet this season.  This just means they continue to grow and creep closer to failure. New snow and wind as well as the warming temperatures this week could act as a catalysts for cornices to fall.  These features deserve extra space and can break farther back than expected. Keep a wide berth both on ridges and when moving below corniced terrain.

Wind slabs: An inch of water was recorded at the Center Ridge Snotel overnight. This could translate to 5-10″ of snow above 3000′ in the Alpine at Turnagain Pass. This combined with sustained easterly winds may have formed tender wind slabs on along ridgelines. Watch for cracking in the snow and pay attention to how well the snow is bonding to the surfaces below. 


Fri, April 1st, 2016

Yesterday was a mixture of sun and clouds across the advisory area. The region saw very warm temperatures with highs in the 50Fs @ 1000′ and in the 40Fs @ 3000′. Winds blew 20-30 mph from the east with gusts into the 50s. Skies clouded up overnight and there were rain showers with the precipitation favoring Turnagain Pass.

Today will be mostly cloudy with continued rain showers and easterly winds 20-35 mph. Temperatures will be in the mid 30Fs to mid 40Fs.

This overall pattern of showers and cloudy skies will persist through the weekend. There is slightly cooler air moving over the forecast area but temperatures will still be above normal.  

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

  Temp Avg (F) Snow (in) Water (in) Snow Depth (in)
Center Ridge (1880′) 45    0 1.1 121  
Summit Lake (1400′)  43  0 0   41  
Alyeska Mid (1700′)  42  0  .1 107  

RIDGETOP 24-hour data (6am – 6am)

  Temp Avg (F) Wind Dir Wind Avg (mph) Wind Gust (mph)
Sunburst (3812′) 39   ENE   26   54  
Seattle Ridge (2400′) 41   SE    26 54  
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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
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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.