Fri, January 24, 2014 Turnagain Pass Avalanche Forecast

Fri, January 24th, 2014

Alpine
Above 2,500'

High (4)

Treeline
1,000'-2,500'

High (4)

Below Treeline
Below 1,000'

High (4)

Alpine Above 2,500'		High (4)
Treeline 1,000'-2,500'		High (4)
Below Treeline Below 1,000'		High (4)

Danger Scale:

No Rating (0)

Low (1)

Moderate (2)

Considerable (3)

High (4)

Extreme (5)

Avalanche Problem 1

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

The West face of Pyramid slid sometime yesterday afternoon. This avalanche ran full path, approximately 3,000’ and took out what appears to be weak snow near the ground and the entire snowpack above it.
Pyramid

With over an inch of water that has fallen in the past 24 hours coupled with another .4” forecasted for today, expect very large natural avalanches like this to remain a possibility. Avoidance is the only way around this avalanche problem for now. As temperatures cool and precipitation diminishes over the weekend expect the likelihood of wet slab and wet loose avalanches to go down.

Up to 2,500′ in elevation the snowpack was isothermal yesterday. Temperatures overnight have remained elevated. In addition to large wet slabs, expect wet loose avalanches in steeper terrain. Avoid being in the runout of larger paths if you happen to find yourself in the lower elevations today.

Avalanche Problem 2

Deep Persistent Slabs

Deep Persistent Slabs

Deep Persistent Slab avalanches are the release of a thick cohesive layer of hard snow (a slab), when the bond breaks between the slab and an underlying persistent weak layer deep in the snowpack. The most common persistent weak layers involved in deep, persistent slabs are depth hoar or facets surrounding a deeply buried crust. Deep Persistent Slabs are typically hard to trigger, are very destructive and dangerous due to the large mass of snow involved, and can persist for months once developed. They are often triggered from areas where the snow is shallow and weak, and are particularly difficult to forecast for and manage.

More info at Avalanche.org

Above treeline the snowpack has been growing over the past week. While our time on or near ridge lines has been limited of late, we know that rain in the lower elevations has equated to heavy snow above 3,000’. The general snowpack structure is poor in the higher elevations, with weak snow sitting at the base. Slabs up to 6’ in depth have the potential to release, take out entire slopes and run far. As freezing levels climb and more precipitation falls today, the likelihood of deep unsurvivable slabs releasing will go up.

Additional Concern

Cornice

Cornice

Cornice Fall is the release of an overhanging mass of snow that forms as the wind moves snow over a sharp terrain feature, such as a ridge, and deposits snow on the downwind (leeward) side. Cornices range in size from small wind drifts of soft snow to large overhangs of hard snow that are 30 feet (10 meters) or taller. They can break off the terrain suddenly and pull back onto the ridge top and catch people by surprise even on the flat ground above the slope. Even small cornices can have enough mass to be destructive and deadly. Cornice Fall can entrain loose surface snow or trigger slab avalanches.

More info at Avalanche.org

Yesterday my partners and I were able to get a look up at several ridge lines. Cornices have grown exponentially over the past week. Similar to Deep Slabs and Wet Avalanches, cornices have the potential to drop onto slopes and trigger very large unsurvivable avalanches. Avoid being in the runout of large avalanche paths today, especially those with large cornices looming above starting zones.

Weather

Fri, January 24th, 2014

Yesterday brought a seventh day of warm and wet conditions. Another ~1.3 € of water in the form of rain fell in the Girdwood Valley. Freezing levels climbed as high as 3,800′.

Sunburst 24 hour summary:
29 F average, 32 F max
28 mph winds out of the East, gust to 74

Today expect another day of similar weather. Up to an additional .4 € of water will fall, winds will be out of the East at 25-35 mph with higher gusts. Freezing level with climb as high as 4,000′ today.

Tomorrow will bring the first break in the wet weather. Skies will clear with valley fog developing. Temperatures will remain mild.

The extended outlook points to a potential high pressure blocking pattern developing by the middle of next week. Pray for snow!

Observations

Recent Observations for Turnagain Pass

Date	Region	Location	Observer
05/22/23	Turnagain	Avalanche: Tincan	Nick D'Alessio
05/12/23	Turnagain	Avalanche: Tincan, Sunburst, Magnum, Cornbiscuit	Heather Thamm
05/07/23	Turnagain	Observation: Tincan – Bear Tracks	CNFAIC Staff
05/05/23	Turnagain	Observation: Seattle Ridge	AS/ WW Forecaster
05/02/23	Turnagain	Observation: Cornbiscuit	Schauer/ Sturgess Forecaster
05/02/23	Turnagain	Observation: Seward Hwy Turnagain Pass	Joel Curtis
04/30/23	Turnagain	Observation: Magnum	Ayla, Kit Crosby, Barton
04/29/23	Turnagain	Observation: Tincan	John Sykes
04/28/23	Turnagain	Avalanche: Taylor Pass/Pastoral	Schauer/ Creighton Forecaster
04/28/23	Turnagain	Avalanche: Tincan	Andy Moderow

Riding Areas

Updated Thu, June 01st, 2023

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 May 15.
Placer River	Closed	Closed May 15.
Skookum Drainage	Closed	Will close to motorized use on April 1, 2023 per the National Forest Plan.
Turnagain Pass	Closed	Will close on June 1.
Twentymile	Closed	Scheduled closure May 1.
Seward District
Carter Lake	Closed	Scheduled closure May 1.
Lost Lake Trail	Closed	Scheduled closure May 1.
Primrose Trail	Closed	Scheduled closure May 1.
Resurrection Pass Trail	Closed	Closed to motorized use for the 2022/23 winter season per Forest Plan. Open next season.
Snug Harbor	Closed	Extended opening until May 15.
South Fork Snow River Corridor	Closed	Scheduled closure May 1.
Summit Lake	Closed	Scheduled closure May 1.