Turnagain Pass RSS

Archives
ARCHIVED - Forecasts expire after 24 hours.
Issued
Sun, January 31st, 2016 - 7:00AM
Expires
Mon, February 1st, 2016 - 7:00AM
Forecaster
Wendy Wagner
Avalanche risk The Bottom Line

Although a generally  LOW  avalanche danger exists in the Turnagain Pass region, there are a few exceptions that are keeping areas of ‘yellow’ in the picture.  These are cornice falls, lingering wind slabs, glide avalanches and sluffs.

First, a  MODERATE  danger exists along ridgelines where  human triggered (or natural) cornice falls are possible and could trigger an old wind slab below. Second, a MODERATE  danger exists at the mid-elevations  where large glide cracks may release into destructive avalanches. And last, watch your sluff, these are expected to be fast moving with moderate to large volumes today.

*If you are thinking of going to the Summit Lake area, be aware that different  avalanche problems  exist within the snowpack. Click  HERE  to read yesterday morning’s Summit Lake Summary.  

Sun, January 31st, 2016
Alpine
Above 2,500'
2 - Moderate
Avalanche risk
Treeline
1,000'-2,500'
2 - Moderate
Avalanche risk
Below Treeline
Below 1,000'
1 - Low
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
  • Cornice
    Cornice
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

After weeks of stormy weather, yesterday finally saw a true break in systems. Clear skies, calm winds and cool temperatures accompanied the many folks enjoying the excellent snow conditions around Turnagain Pass. With literally several hundred slope testers out there, the only avalanche activity seen and/or reported was several cornice falls and, believe it or not, one large ‘natural’ avalanche… (Many reports and photos were sent into us, check them out HERE!)

This avalanche was on the West face of Lipps ridge and released at 1pm yesterday. Skiers on the Cornbiscuit ridge reported seeing a powder cloud and snow in motion. At this point the trigger is unknown. There were skiers on the Lipps South face skin track; around the corner. There were no tracks leading into or out of the slide and no tracks near it on the ridge. We suspect this was a large wind slab triggered by a natural cornice fall. We have not seen any persistent weak layers that would lead us to believe this was remotely triggered by skiers on the South face. If anyone has further information on this slide please send us an observation or an email! 

Photo of the Lipps avalanche. Many more photos can be seen HERE.

 

Cornice falls and wind slabs today? 
With another clear sky day and light winds on tap, we are expecting very similar ‘mostly’ stable avalanche conditions. This means watching for lingering wind slabs in very steep rocky terrain and giving cornices a wide berth – see photo below. The sun is just starting to affect the snow and could help tip the balance for cornices on the verge of breaking. Keeping a look out for stiff hollow feeling snow and smooth wind pillows are good ways to suss out wind slabs on the steeper slopes.

**Although the snowpack is generally stable, the size and dangerous nature of the Lipps avalanche gives us pause to send out a green light today. Low danger incorporates small avalanches to be possible but not large ones. This ‘outlier’ avalanche is why keeping with good habits is ALWAYS important at times of good stability. These include:

– Exposing only one person at a time on a slope
– Grouping up in safe zones
– Having an escape route planned if the slope slides
– Communicating plans with your partners

Photos below: Left photo (by Adrian Beebee), skier track on a chunk of cornice that was triggered on Tincan – close call!!  Right photo (Louis Sass), large natural cornice fall in upper Lyon creek.
  

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

We were expecting a glide release or two yesterday with the cooler temperatures and clearing skies but, no, we did not see any. It looks as though the glide cycle may be slowing down? Regardless, limiting/avoiding time under glide cracks remains prudent.

Sometimes it’s hard to know if you are under a yawning glide crack if you can’t see the whole slope.

Additional Concern
  • Dry Loose
    Dry Loose
Dry Loose
Dry Loose avalanches are the release of dry unconsolidated snow and typically occur within layers of soft snow near the surface of the snowpack. These avalanches start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-dry avalanches include point-release avalanches or sluffs.
More info at Avalanche.org

Sluff management! This will be one of those days that sluffs could be large, run quickly and catch you if you’re not looking. 

Sluffs from yesterday:

Weather
Sun, January 31st, 2016

Yesterday’s nice day consisted of clear skies, light and variable winds and temperatures in the upper teens to low 20’s F.  

Overnight temperatures have warmed at the upper elevations and cooled at the lower. An inversion is in place this morning with ~25F on the ridgetops and ~15F at 1,000′. Skies remain clear and should stay that way for today. We can expect temperatures to warm slightly through the day with the winds turning Easterly and picking up to the 10-15mph range by sunset.  

Monday, we are expecting a weak frontal band to move through from the East. A bump in Easterly winds, cloud cover and a chance for 1-2″ of snow is expected.

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

  Temp Avg (F) Snow (in) Water (in) Snow Depth (in)
Center Ridge (1880′) 23   0    0 95  
Summit Lake (1400′) 19    0  0 27  
Alyeska Mid (1700′) 24   0    0 72  

RIDGETOP 24-hour data (6am – 6am)

  Temp Avg (F) Wind Dir Wind Avg (mph) Wind Gust (mph)
Sunburst (3812′) 23   variable 5   10  
Seattle Ridge (2400′) 23   N/A   N/A     N/A    
Observations
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.