Turnagain Pass RSS

Archives
ARCHIVED - Forecasts expire after 24 hours.
Issued
Thu, April 14th, 2016 - 7:00AM
Expires
Fri, April 15th, 2016 - 7:00AM
Forecaster
Heather Thamm
Avalanche risk The Bottom Line

The avalanche danger is  CONSIDERABLE below 2500′ due to a continued pattern of warm temperatures and an active glide avalanche cycle. Glide cracks have been releasing daily and without warning, and travel is not recommended in terrain with existing glide cracks (including the uptrack on the motorized side of Turnagain Pass.) Human triggered wet-loose avalanches will be possible on slopes steeper than 35 degrees and will be more likely later in the day with warming temperatures.

In the Alpine, above 2500′, a generally LOW avalanche danger exists. LOW danger does not mean NO danger €“ Be aware of your exposure in steep terrain and give large cornice extra space €“ these features should never be trusted.

*ATTENTION HIKERS: Summer use trails with avalanche terrain above should be avoided due to avalanche activity from above. Byron trail in Portage Valley and Crow Pass are two examples of trails not recommended right now.  

Special Announcements
  • This is the final week of  daily  avalanche advisories. Between Monday, April 18th and Saturday, April 30th we will be issuing advisories on weekends and intermittently during the week
  • The Chugach National Forest has closed some riding areas to motorized use due to snow melting out. Please see the table at the bottom of this page for a complete list. Snug Harbor, Summit Lake and  Turnagain Pass (N. of Granite creek)  remain open.  
Thu, April 14th, 2016
Alpine
Above 2,500'
1 - Low
Avalanche risk
Treeline
1,000'-2,500'
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
  • 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

Glide cracks continue to be actively releasing in popular terrain throughout our region including recent activity on Repeat Offender (photo below). Travel underneath existing glide cracks is a total gamble. The zone above and around the popular motorized up-track on Seattle Ridge continues to have our hackles up. This well traveled slope is hanging in the balance (pictured below). Although much of the snowpack has already avalanched along Seattle Ridge, there is still a lot of snow that could release. There was no overnight freeze in the 1000-2000′ elevation band and there is the possibility of rain today. These weather factors may increase glide activity.

Due to the dangerous and destructive power of even a small glide avalanche, we are recommending that people do not travel in avalanche terrain (including runout zones) on the motorized side of Turnagain Pass (West Side). Glide avalanche hazard also exists on the non-motorized side of Turnagain Pass. Travel underneath existing glide cracks is not recommended; if you were to be in the wrong place at the wrong time getting caught up in a glide avalanche would not be survivable. 

Flat light and distance make it hard to see small cracks that have formed in the rocks directly above the up-track, looker right side of the photo.

 

 

A small glide release was observed on Repeat Offender last night with the DOT web camera just after 7pm. Before and after pictures below. 

 

Avalanche Problem 2
  • 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

Below 2000’ we have seen multiple days without freezing temperatures and yesterday’s sun left the snowpack wet and saturated in the mid elevation zone. This combined with the possibility of rain will up the likelihood and potential for human triggered wet loose avalanches today. If the snow becomes unsupportable and your skis/snowmachine start sinking into punchy wet snow, this is an obvious sign the snow is loosing its strength. Remember wet loose avalanches can be hard to escape once initiated and particularly hazardous if they push you into a terrain trap. 

 

Skier triggered rollerballs were easy to initiate by 3pm in the mid elevation zone yesterday. This was on a small slope of about 35 degrees.

Additional Concern
  • Normal Caution
    Normal Caution
Normal Caution
Normal Caution means triggering an avalanche is unlikely but not impossible.
More info at Avalanche.org

Today it will be important to be aware of terrain features that could harbor isolated instabilities in the Apline, above 2500′. Cornices remain large and warm daytime temperatures will be adding additional stress. Give them extra space and remember they have a tendency to break much further back than expected. On shaded aspects triggering an old wind slab will be especially dangerous in high consequence terrain. Ease into steep terrain with caution and be aware features (rocks and cliffs) where taking a fall would be undesired.  

Weather
Thu, April 14th, 2016

Yesterday skies were partly to mostly cloudy with periods of sunshine throughout the day. At Center Ridge Weather station (1880′) daytime temperatures remained warm with a high of 47F mid-day and overnight temperatures hovering just above freezing level (33F.) Ridgetop winds were light from the East and a trace of precipitation (0.1 €) was recorded overnight.

Light scattered showers are expected throughout the day with mostly cloudy skis. This will be in the form of rain below 2500′, around 0.1 € of (snow water equivalent.) Light Ridgetop winds, 5-15mph, will be from the East.  Daytime highs for 1000′ will be in the mid 40F’s again and overnight lows in the mid 30F’s.

A similar pattern is expected again on Friday, but with a higher chance of rain/snow showers.

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

  Temp Avg (F) Snow (in) Water (in) Snow Depth (in)
Center Ridge (1880′) 39   rain 0.1   113  
Summit Lake (1400′) 40   0   0   30  
Alyeska Mid (1700′) 38   rain   0.01   98  

RIDGETOP 24-hour data (6am – 6am)

  Temp Avg (F) Wind Dir Wind Avg (mph) Wind Gust (mph)
Sunburst (3812′) 31   ENE   9   17  
Seattle Ridge (2400′) 32   SE   13   19  
Observations
Recent Observations for Turnagain Pass
Date Region Location Observer
04/16/24 Turnagain Observation: Cornbiscuit Krueger / Matthys Forecaster
04/15/24 Turnagain Observation: Taylor Pass John Sykes Forecaster
04/15/24 Turnagain Observation: Seward Highway – Tern Lake to Portage Joel Curtis
04/14/24 Turnagain Observation: Sunburst T. Olsen-Lund, R. Sullivan I. Adams
04/14/24 Turnagain Observation: Turnagain Pass Snomo K. Gallaher
04/13/24 Turnagain Observation: Spokane Creek Everet Megli
04/11/24 Turnagain Observation: Tincan John Sykes Forecaster
04/10/24 Turnagain Avalanche: Seattle Ridge Schauer/ Keeler Forecaster
04/10/24 Turnagain Observation: Cornbiscuit South Face Todd Kelsey
04/10/24 Turnagain Avalanche: Tincan N. Dumont J. Carlberg
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.
Become a Member
If you think a public avalanche center is important please support our organization.
Donate Now
Become a Sponsor
Supporting the CNFAIC proudly shows that your business or organization values the safety of our snow sports community.
Become a Sponsor