Turnagain Pass RSS

Archives
ARCHIVED - Forecasts expire after 24 hours.
Issued
Sun, February 14th, 2016 - 7:00AM
Expires
Mon, February 15th, 2016 - 7:00AM
Forecaster
Wendy Wagner
Avalanche risk The Bottom Line

There is a MODERATE avalanche danger in the mountains surrounding Turnagain Pass for a variety of avalanche problems. First, glide avalanches, that release on their own, are possible at the Treeline elevation band (1,000-2,500). Second, human triggered wet loose avalanches will be possible at this same Treeline band. Third, Wind slab avalanches, up to 2′ thick, and cornice falls are possible in the Alpine (above 2,500′) where it has been lightly snowing and blowing.

Special Announcements

We had a GREAT turnout at the 2nd annual Hatcher Pass Avalanche Rescue Workshop!! Over 70 people attended this community supported clinic. A big thanks to the Hatcher Pass Snow Riders Club for hosting a BBQ afterward. This workshop was put on by Hatcher Pass Avalanche Center in partnership with the Friends of the CNFAIC.  

Don’t forget about the  FREE avalanche awareness class in Palmer Wednesday, February 17th. Everyone is welcome, no registration. It is from 6:30-8pm at the Palmer High School Library. Click  HERE  for more information!

 

 

Sun, February 14th, 2016
Alpine
Above 2,500'
2 - Moderate
Avalanche risk
Treeline
1,000'-2,500'
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. Dangerous avalanche conditions. 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

Although there are many human triggered avalanche concerns out there, glide avalanches remain the primary concern due to their destructive nature. This season is turning out to be a season where mapping glide cracks and limiting/avoiding time under them is just part of the game. The most recent glide we know of that has released at Turnagain Pass was 3-4 days ago on the Eddies ridge. 

Photo: Glide avalanche on Eddies, released sometime late 2/10-early 2/11.

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

While many folks are waiting for the skies to clear and temperatures to cool off before venturing into the mountains, it has been snowing a bit and blowing quite a bit over the past several days in the Alpine – above 2,500′. Specifically, between 1 and 2 feet of new snow has fallen over the past 3 days with winds in the 20-25mph range on the ridgetops from the East. Due to lack of travel and visibility in these areas we don’t have first hand data as to how the wind driven snow is bonding, if cornices are falling and the like. However, we know from past experience that this warm snow is quite sticky and stabilizes relatively quickly. This will most likely be the case for today and into the week. Nonetheless, things to watch for at the upper elevations:

Wind Slabs:  Steep slopes that have been, or are currently being, loaded with wind deposited snow are suspect for triggered a wind slab avalanche. These could be 1-2′ or more thick. Watching for cracking in the new snow and jumping on small terrain features and test slopes can be good ways to see how well slabs are bonding. 

Cornice Falls: GIVE CORNICES a wide berth!! these are likely to be tender with the warm temperatures and could be deadly if you were to take a fall off a ridgeline with one. Also, similar to glide avalanches, limit time spend under cornices.

*Shallow snowpack zones: South of Turnagain Pass and the Summit Lake area. These areas have old weak layers in the snowpack that, if loaded with enough snow/wind, could produce a large avalanche. This is something to keep in mind if you are headed to these zones this week with the expected clear skies.

Additional Concern
  • 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

It will be another moist day out there. Temperatures dipped to 32F at 1,000′ overnight and it is lightly snowing at the Pass this morning, but temperatures are forecast to climb up again today. Rain up to 1,500′ is possible and we have .2-.4″ of it with 2-4″ of snow in the Alpine. The snow at the mid-elevations is wet and saturated. These are prime conditions for triggering a wet loose avalanche on steep slopes. To initiate a wet loose slide the slope has to be quite steep, but once it starts moving can gain a lot of momentum and run to valley bottoms. Steering clear of steep slopes with ‘boot-top’ wet snow is an avalanche forecaster’s rule of thumb.

Weather
Sun, February 14th, 2016

Partly cloudy skies with some blue holes covered the region yesterday. Light precipitation fell, adding ~.2″ of rain below 1,000′, and was mostly centered around Turnagain Arm. Around 2″ of snow has fallen in the past 24-hours above 1,500′. Temperatures dropped to 32F at 1,000′ and are holding steady in the mid 20’s on the ridgelines. Winds have been sustained in the moderate range with averages 20-25mph from the East along the ridgetops.  

For today, we are expecting mostly cloudy skies along with light precipitation. Between .2-.4″ of rain is expected to fall below 1,500 with 2-4″ of wet snow above this. The rain/snow line is currently around 800′ this morning but looking to climb a bit through the day. Ridgetop winds are expected to remain moderate from the East, 20-25mph. Temperatures remain warm, mid 30’s F at 1,000′ and mid 20’s F at 3,500′.

For Monday we remain in this unsettled warm and showery pattern, but for Tuesday we could see cooler temperatures and a real break in weather.  

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

  Temp Avg (F) Snow (in) Water (in) Snow Depth (in)
Center Ridge (1880′)  32 3    0.3 104  
Summit Lake (1400′) 34   0    0 30  
Alyeska Mid (1700′) 33   1.5    0.15 84  

RIDGETOP 24-hour data (6am – 6am)

  Temp Avg (F) Wind Dir Wind Avg (mph) Wind Gust (mph)
Sunburst (3812′) 24   NE   22   54  
Seattle Ridge (2400′) 27   –   –   –  
Observations
Recent Observations for Turnagain Pass
Date Region Location Observer
11/16/23 Turnagain Observation: Tincan Common William Finley
11/14/23 Turnagain Observation: Sunburst/Magnum Adrian Beebee
11/14/23 Turnagain Observation: Seattle Ridge Schauer/ Creighton/ Ellis Forecaster
11/13/23 Turnagain Avalanche: Tincan Trees Eeva Latosuo
11/12/23 Turnagain Observation: Sunburst Schauer/ Creighton/ Nave Forecaster
11/12/23 Turnagain Avalanche: Goldpan – avalanche Mike Records
11/11/23 Turnagain Observation: Tincan Common Andy Moderow
11/11/23 Turnagain Observation: Taylor Pass – Sunburst Wadsworth / Stwertka
11/10/23 Turnagain Observation: Tincan Andrew Schauer Forecaster
11/10/23 Turnagain Observation: Tincan Trees Michael Kerst
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