Turnagain Pass RSS

Archives
ARCHIVED - Forecasts expire after 24 hours.
Issued
Sat, January 23rd, 2016 - 7:00AM
Expires
Sun, January 24th, 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 two exceptions that are keeping ‘yellow’ in the picture.  These are glide and wind slab avalanches.

First, a  MODERATE danger exists at the mid-elevations where destructive glide avalanches remain possible. Limiting time, or avoiding altogether, exposure under glide cracks is highly recommended. Second, a MODERATE danger exists at the high elevations where fresh wind slabs ~6-10″ thick may be found on any aspect. These slabs are expected to be scattered near ridgelines that have seen recent, or current, wind loading. Also, don’t forget to give cornices a wide berth, these are large and looming.

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 this morning’s Summit Lake Summary.  

Special Announcements
  • Monday, January 25th, 7-8 pm:  Come to the Blue and Gold Board Shop for a FREE Avalanche Awareness class taught by CNFAIC forecaster Heather Thamm. For more details click here:  HERE.  Know Before You Go!
Sat, January 23rd, 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
  • 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

It’s like a lingering cold that just won’t go away…… glide cracks linger, and litter, the mid-elevation slopes around Turnagain Pass. They continue to slowly open and every once in a while one will release. The last known release was on Sharks Fin (South facing ~2,000′) either late Wednesday or early Thursday. Since these avalanche spontaneously at any time, it is best to avoid, or do your best to limit time under, glide cracks. With questionable visibility again today, it may be difficult to identify glide cracks. 

Photo below: These are two glide avalanches that released one week ago on Seattle Ridge above the motorized parking lot. There are still three very prominent cracks that look to be on the verge of releasing next to these two.

Avalanche Problem 2
  • Wind Slabs
    Wind Slabs
Wind Slabs
Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind 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

With an overall generally stable snowpack we are dealing these days with ‘surface instabilities’. Shallow wind slabs in steep terrain are the most likely avalanche that could be triggered by snowmachiners, skiers or snowboarders today. Between 1 and 4″ of snow fell overnight and we have another 1-3″ of light snow in the forecast today. Add to this, moderate ridgetop Easterly winds and we have shallow wind slabs. These are most likely going to be right near ridgelines where the wind is blowing. I’m guessing there will be ridgelines that have very little wind and hence no wind slab issue and a LOW avalanche danger.

If the skies clear enough for travel to the Alpine zones, watch for recent wind drifted snow and stiffer snow over softer snow. Good ways to do this are getting off old snowmachine tracks, or off the skin track, and using your boot or pole to feel what the surface layers do. Does your boot or pole punch through to softer snow? Or, is there a progression from soft to stiffer snow? Remember too, this needs to be done in areas representative of where you are looking to ride and/or ski.

Weather
Sat, January 23rd, 2016

Yesterday’s weather consisted of overcast skies with light snow falling on the North side of the Pass (rain up to1,000′). Winds on the ridgetops were light to moderate from the East. Temperatures were mild….34F at 1,000′ and in the upper 20’s in the Alpine.

Overnight we picked up 2-3″ of new snow above 1,200′ with rain below. Less amounts on the South side of Turnagain Pass. For today, we should see intermittent snowfall above 1,200′ and rain below. Again precipitation intensity will be higher near the Arm and less over the inland areas. Skies should be cloudy with possible patches of blue here and there and temperatures near freezing. Ridgetop winds should be in the 10-15mph range with stronger gusts.

Sunday is looking to be similar with intermittent precipitation, mild temperatures and possible breaks in cloud cover.

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

  Temp Avg (F) Snow (in) Water (in) Snow Depth (in)
Center Ridge (1880′) 31    2 0.2   86  
Summit Lake (1400′) 30  0 0   27  
Alyeska Mid (1700′)  32  2.5 0.37   69  

RIDGETOP 24-hour data (6am – 6am)

  Temp Avg (F) Wind Dir Wind Avg (mph) Wind Gust (mph)
Sunburst (3812′) 25   ENE   12   33  
Seattle Ridge (2400′) 27   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.