Turnagain Pass Avalanche Forecast RSS

Archives
ARCHIVED FORECAST - All forecasts expire after 24 hours from the posting date/time.
Issued
Wed, January 8th, 2014 - 7:00AM
Expires
Thu, January 9th, 2014 - 7:00AM
Forecaster
Graham Predeger
Avalanche risk The Bottom Line

The avalanche danger today remains at CONSIDERABLE above treeline where the potential exists to initiate large slab avalanches 2-3′ deep.   An avalanche triggered today has the potential to propagate across entire slopes in surprising and unpredictable ways.   Cautious route finding and conservative decision-making will again be essential elements to a fun, safe day in the backcountry.

Below treeline the danger remains MODERATE due to the continued, around the clock above freezing temperatures and weak snow found near the base of the snowpack.

Thanks to our sponsors!
Wed, January 8th, 2014
Alpine
Above 2,500'
Considerable (3)
Avalanche risk
Treeline
1,000'-2,500'
Moderate (2)
Avalanche risk
Below Treeline
Below 1,000'
Moderate (2)
Avalanche risk
Alpine
Above 2,500'
Avalanche risk
Considerable (3)
Treeline
1,000'-2,500'
Avalanche risk
Moderate (2)
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
  • Persistent Slabs
    Persistent Slabs
Persistent Slabs
Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.
More info at Avalanche.org

We haven’t heard of any new avalanche activity since Sunday, when a substantial natural avalanche cycle occurred in addition to a second-hand report of snowmachine-triggered avalanche activity near Seattle ridge.  This most recent cycle has a common theme in the fact that all of these avalanches have been quite large, propagating across entire slopes with faceted snow near the ground proving the common and persistent weak layer. Recent results from the snowpit show these weak layers have been slow to gain strength as Fitz’s video here points out.  This is a great example of the persistent slab problem that has dominated our primary concern over much of the last three weeks.

As few people have been venturing into the backcountry since the Jan. 5th storm, our information is limited.  What information we do have, points toward a snowpack hanging in the balance with a poor structure, moderate strength and high energy.  In a nutshell this means that if a fracture is initiated on or below a slope steep enough to avalanche (> 35 degrees) there is good potential that the crack will propagate far and wide, creating a large and unmanageable avalanche.  Likely trigger points include thin spots in the slab or near rocks and trees mid-slope.

Maintain astute situational awareness and be mindful of any obvious signs of instability if you travel into the backcountry today.  Conservative terrain selection and proper travel protocol will be key.

In areas below treeline where the surface snow is still wet, exists a very poor snowpack structure with free water percolating throughout.  Once overnight temperatures maintain below the freezing mark, this lower elevation snowpack will ‘lock-up’ and we’ll likely see Low danger in this elevation band.

Weather
Wed, January 8th, 2014

Southeast flow continued yesterday ushering in warm temperatures and intermittent bands of rain through the eastern Turnagain arm region with no measurable snow accumulation to speak of.   Winds have been light to moderate predominantly from the East and temperatures remained in the 20’s at ridgetop locations and mid-30’s at 1000 feet.

Today looks to be the start of a gradual cool down with temperatures moderating back to near normal values by the weekend.   Cloudy skies and 28-33 degrees should usher in 2-3 € of snow above 1000 feet today with slightly warmer temperatures and a rain/ snow mix at sea level.   Winds will be out of the East at 15-25 mph and look to  decrease to single digits from the North by tonight.

Observations
Recent Observations for Turnagain Pass
Date Region Location
04/21/21 Turnagain Observation: Sunburst
04/19/21 Turnagain Avalanche: Triangle, Seattle creek
04/18/21 Turnagain Avalanche: Turnagain Pass Road Obs
04/18/21 Turnagain Observation: Seattle Ridge, approximately 300 yards south of the up track
04/17/21 Turnagain Avalanche: Road obs
04/16/21 Turnagain Avalanche: Seattle Ridge
04/16/21 Turnagain Avalanche: Turnagain Pass, non-motorized side seen from Seattle Ridge
04/16/21 Turnagain Observation: Sunburst
04/15/21 Turnagain Observation: Tincan
04/13/21 Turnagain Observation: Turnagain Pass Road Obs
Riding Areas
Updated Tue, April 20th, 2021

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
Open
No parking in turnaround at end of the road near the outhouse.
Placer River
Open
Please do not ride along Railroad tracks. Cross tracks at 90 degree angle and clear the right of way.
Skookum Drainage
Closed
The Skookum Valley is closed to snowmachines. This closure occurs annually on April 1 as per the CNF Forest Plan.
Turnagain Pass
Open
Twentymile
Closed
Seward District
Carter Lake
Open
Lost Lake Trail
Open
Primrose Trail
Open
Resurrection Pass Trail
Closed
Closed for the 2020/21 winter season.
Snug Harbor
Open
South Fork Snow River Corridor
Open
Summit Lake
Open

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.