Turnagain Pass Avalanche Forecast RSS

Archives
ARCHIVED FORECAST - All forecasts expire after 24 hours from the posting date/time.
Issued
Fri, February 5th, 2016 - 7:00AM
Expires
Sat, February 6th, 2016 - 7:00AM
Forecaster
Aleph Johnston-Bloom
The Bottom Line

The avalanche hazard is  HIGH  above 1000′. Large natural and human triggered avalanches are likely today.  Over 3″ of water (+3′ of snow above 1500′) has fallen since Tuesday night and is resting on weak snow over a crust. This set-up combined with strong winds and warm temperatures have created very dangerous conditions in the backcountry. Additional snow, rain and wind will continue to stress the snowpack.  Travel in or near avalanche terrain is NOT recommended today.  

Below Treeline ( -1000′) a  MODERATE  danger exists where an avalanche in steep channeled terrain could run into this elevation band.

Thanks to our sponsors!
Fri, February 5th, 2016
Alpine
Above 2,500'
High (4)
Avalanche risk
Treeline
1,000'-2,500'
High (4)
Avalanche risk
Below Treeline
Below 1,000'
Moderate (2)
Avalanche risk
Alpine
Above 2,500'
Avalanche risk
High (4)
Treeline
1,000'-2,500'
Avalanche risk
High (4)
Below Treeline
Below 1,000'
Avalanche risk
Moderate (2)
Danger Scale:
No Rating (0)
Low (1)
Moderate (2)
Considerable (3)
High (4)
Extreme (5)
Avalanche Problem 1
  • 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

Storm Slabs: Today is day 3 of a warm and wet storm that has dumped 3″ of water (2-4′ of new snow in the upper elevations) in the advisory area. This has fallen on old weak (faceted) snow resting on a rain crust. The storm snow was not bonding well to this yesterday and was reactive in tests, whumpfing, cracking and became increasingly ‘slabby’ throughout the day. Because the crust/facet combo extends from 1000′ to approximately 3000′ avalanches could be very large and connected. The storm last week stabilized quickly. It is important to recognize the character of this set-up is very different and could elevate the hazard through the weekend. Travel in avalanche terrain is not recommended today. 

Wind SlabsStormy conditions continue to make wind slabs a concern for the upper elevations. Sustained 30-40 mph ENE winds, gusting in the 70s yesterday, have made triggering a wind slab +3’ thick likely on wind loaded and cross-loaded features. Below 3000’ these wind slabs are sitting on the old snow/crust combo and may propagate further than expected. 

Cornices: Cornices will be unstable today and may release naturally. These features have been tender over the last week and now have the added stress of high winds and new snow. These backcountry bombs can easily trigger a slab below and are another reason to avoid travel in avalanche terrain today.  

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

Wet Snow: Wet snow is sitting on a slick crust in the mid elevation band. Rain to 1600’ will be lubricating this poor interface making wet avalanches possible in the mid elevation band. This hazard will be especially dangerous under big open slopes and in terrain traps like gullies or abrupt transitions where an avalanche from above could have high consequences. Natural activity is possible in steep channeled terrain and will likely entrain wet snow. Areas like lower Seattle Ridge should be avoided. 

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

Warm temperatures, rain and wet snow continue to add weight and stress to glide cracks throughout Turnagain Pass. These unpredictable hazards are widespread in steep terrain between 1000’ to 2500’ and can release without warning. Today’s limited visibility will make it challenging to identify existing glides, and is an added reason to avoid being in the mountains today. 

 

Weather
Fri, February 5th, 2016

Yesterday was a storm day. Rain fell up to 1500′ and the advisory area recieved another 1.5″ of moisture. Snowfall was up to an 1″/hr for much of the day with over 1′ of new snow falling in the last 24 hrs. Since Tuesday evening 3″ of water and +3′ of snow have fallen. Winds were from the ENE blowing 30-40 mph gusting into the 70s. Temperatures were in the 30Fs at 1000′ and the mid-20Fs at 3000′.  

Rain and snow showers are forecasted to continue today with an addtional 0-4” of snow and rain up to 1600′. Winds will be Easterly 15-25 mph and temperatures will be in the 30s.  

Showers continue this evening tappering off overnight with a short break before the next Low impacts the area Sunday.  

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

  Temp Avg (F) Snow (in) Water (in) Snow Depth (in)
Center Ridge (1880′) 31    10 1.7   114  
Summit Lake (1400′) 32  3  .3  31
Alyeska Mid (1700′) 32  9.5  1.3  84

RIDGETOP 24-hour data (6am – 6am)

  Temp Avg (F) Wind Dir Wind Avg (mph) Wind Gust (mph)
Sunburst (3812′) 24    ENE  34 76  
Seattle Ridge (2400′) 26  n/a n/a   n/a  
Observations
Recent Observations for Turnagain Pass
Date Region Location
12/08/19 Turnagain Avalanche: Tincan
12/06/19 Turnagain Avalanche: Sunburst
12/04/19 Turnagain Observation: Sunburst
12/03/19 Turnagain Observation: Hippy Bowl
12/01/19 Turnagain Observation: Tincan, All elevations
12/01/19 Turnagain Observation: Tincan
11/30/19 Turnagain Observation: Tincan Treeline Plateau/ Common Bowl/ Ridge
11/29/19 Turnagain Observation: Sunburst Ob #2
11/29/19 Turnagain Observation: Sunburst Ob #1
11/27/19 Turnagain Observation: Tincan
Riding Areas
Updated Mon, December 02nd, 2019

Status of riding areas across the Chugach NF is managed by the Glacier and Seward Ranger Districts, not avalanche center staff. Riding area information is posted as a public service to our users and updated based on snow depth and snow density to prevent resource damage at trailhead locations. Riding area questions contact: mailroom_r10_chugach@fs.fed.us

Area Status Weather & Riding Conditions
Glacier District
Johnson Pass
Closed
Closed.
Placer River
Closed
Closed.
Skookum Drainage
Closed
Closed.
Turnagain Pass
Closed
Closed.
Twentymile
Closed
Closed.
Seward District
Carter Lake
Closed
Closed.
Lost Lake Trail
Closed
Closed.
Primrose Trail
Closed
Closed.
Resurrection Pass Trail
Closed
Closed. Will be open for the 2019/20 season pending adequate snow cover.
Snug Harbor
Closed
Closed.
South Fork Snow River Corridor
Closed
Closed.
Summit Lake
Closed
Closed.

Subscribe to Turnagain Pass
Avalanche Forecast by Email