Sat, February 08, 2014 Turnagain Pass Avalanche Forecast

Sat, February 8th, 2014

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

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

Fresh wind slab from yesterday’s storm is the most likely problem to find today. This should be a manageable avalanche concern – not dangerous unless you jump into high consequence terrain without sluffing out the run first. I expect a lot of slopes will be easily triggered by skiers today, but this is light density snow and should behave in a predictable manner. It’s the perfect scenario for controlled ski cutting (in areas of safe terrain exposure). The CONSIDERABLE danger rating is for likely human triggered avalanches – of small size, in many areas.

The good skiing will probably be sheltered areas where wind didn’t have a lot of effect.

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

We’ve been tracking multiple buried weak layers for quite some time. The big meltdown in January caused many large deep slab avalanches, but since cooler temperatures took over, the mountains have gone dormant. We still have some concerns about the persistent weak layers (persistent means they stick around for a long time). The areas of greatest concern include elevations above 3500 feet where the rain and warm temperatures had less effect on the snowpack. It may still be possible for a person to initiate a collapse and trigger a deep avalanche.

This is a MODERATE type concern of low likelihood but higher consequence.

Weather

Sat, February 8th, 2014

The big news in the weather history is the storm that blew through yesterday. Areas hardest hit by this storm appear to be glacier regions of the southeast Kenai peninsula, Prince William Sound, Turnagain Pass (16 inches?) and Grandview (10-12 inches). If instrumentation is reading correctly, snow density is somewhere around 5%, or very light dry powder. Wind at the ridgetops was blowing 40s-60s mph on Sunburst from an ENE direction. Temperatures during the storm started cold, in the teens and low 20s and rose to what they are currently (mid to high 20s).

Today – mostly cloudy skies, temperatures in the 20s, and a light NW wind.

Weather trend looks to be colder and windier from the north going into next week. No major storms are on the horizon for the coming week.

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.