Mon, March 25, 2013 Turnagain Pass Avalanche Forecast

Mon, March 25th, 2013

Alpine
Above 2,500'

Considerable (3)

Treeline
1,000'-2,500'

Moderate (2)

Below Treeline
Below 1,000'

Moderate (2)

Alpine Above 2,500'		Considerable (3)
Treeline 1,000'-2,500'		Moderate (2)
Below Treeline Below 1,000'		Moderate (2)

Danger Scale:

No Rating (0)

Low (1)

Moderate (2)

Considerable (3)

High (4)

Extreme (5)

Avalanche Problem 1

Dry Loose

Dry Loose

Dry Loose avalanches are the release of dry unconsolidated snow and typically occur within layers of soft snow near the surface of the snowpack. These avalanches start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-dry avalanches include point-release avalanches or sluffs.

More info at Avalanche.org

In areas unaffected by wind expect to encounter enough light density snow for riders and skiers to create small to medium sized loose snow avalanches. The only reactive snow we were able to find yesterday was a few inches of this light density loose snow. In terrain over 40 degrees this surface snow slid readily in the form of sluffs and was low in volume and fast moving. Expect more of the same behavior today with volumes increasing as the snow accumulates. Human triggered sluffing has the potential to carry people into and over terrain traps. Choose your terrain with this in mind today.

Storm Snow

New snow in the form of slabs will also be a concern. Expect slabs up to 18″ in depth to be most sensitive on steep south facing terrain today.

Avalanche Problem 2

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

Look for wind slabs to build today in the upper elevations on west and south aspects. These slabs will be most sensitive on steep south facing terrain where a stout crust lurks beneath the surface and will provide for a good sliding surface. We have had several reports of skier triggered avalanches mainly on south aspects over the weekend. This setup of new snow bonding poorly to crusts primarily exists on terrain over 35 degrees.

Additional Concerns

Persistent Slab
Old wind slabs, formed by strong winds of last Tuesday are lingering below a fresh coating of snow. These slabs are sitting on weak snow, are somewhat random in their distribution, and concealed by 2-8″ of new snow. Because of this they are hard to detect. Staying off of steep terrain (>40 degrees) will help to minimize your chances of finding one of these isolated pockets of slab.

Cornices
The most destructive avalanches we have seen over the past three weeks have been the result of large cornice falls. Minimize your time on terrain with cornices sitting above and approach ridgecrests with caution.

Weather

Mon, March 25th, 2013

In the past 24 hours the mountains around Eastern Turnagain Arm on average have picked up ~6″ of new snow with .6″ of water. Temperatures at the Seattle Ridge station at 2,400′ averaged 22.5 F. Winds there have averaged 10 mph out of the ESE with gusts to 22mph.

Light snow continues to fall in the area and should continue through the evening hours with 6-10″ expected. The peak intensity for snowfall will occur in the morning hours today. Winds will pick back up later in the day and average 15-25mph out of the E. Temperatures at 1,000′ will stay in the high teens to low 20s F today.

The extended outlook calls for clearing on Tuesday with a return to an active (snowy) weather pattern for the second half of the week.

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Wendy will issue the next advisory tomorrow morning, March 26th.

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.