Thu, January 31, 2013 Turnagain Pass Avalanche Forecast

Thu, January 31st, 2013

Alpine
Above 2,500'

Moderate (2)

Treeline
1,000'-2,500'

Low (1)

Below Treeline
Below 1,000'

Low (1)

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

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

Tender wind slabs will once again dominate the discussion today as the primary avalanche concern. Yesterday these wind slabs were shallow and easily triggered on steep convex slopes. With the added wind yesterday and a few more inches of snow overnight we can expect these wind slabs to have gained in depth and mass. The deeper, more dangerous pockets will be found on slopes with a westerly tilt at and above tree line where these slabs are resting on a smooth and supportable crust. At higher elevations where the crust is not present, there is some uncertainty as to how well this most recent snow is bonding. It will be sensible today to pay attention to any red flags including shooting cracks, whumphing or recent avalanches. These are your bulls-eye clues that instability in the snowpack exists.

Shooting crack in shallow wind slab at 2500′. Jan. 30th, 2013. Petes North

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

This problem has been dormant for some time now. It’s unlikely this most recent storm will provide enough of a punch to wake up this problematic layer. However, it is prudent to continue to be suspect of steep, shallow and rocky terrain above tree line where it is more likely a human could impact this deeper, weak snow.

Weather

Thu, January 31st, 2013

Forecasted precipitation fell a little flat for us yesterday and last night with the Turnagain pass region only picking up about 1-2 € of new snow. Winds have dropped off substantially overnight as this latest front weakens and moves out of our area.

This last day of January doesn’t look to be like much of a weather producer in our region. Temperatures are expected to be in the low 30’s at 1000′, winds light from the east and less than an inch of new snow in the forecast. Another weak front moves into the gulf tomorrow ushering in a chance for snow/ rain in south central as we head into the weekend.

January 2013 comes to an end with 9.1 € of water and 71 € of snow (preliminary numbers), most of which fell in the first half of the month.

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Fitz will issue the next advisory tomorrow morning, February 1st.

Observations

Recent Observations for Turnagain Pass

Date	Region	Location	Observer
05/28/22	Turnagain	Avalanche: Turnagain Pass – late May wet slab cycle	CNFAIC Staff
05/21/22	Turnagain	Avalanche: Magnum, Lipps and Tincan	CNFAIC Staff
05/17/22	Turnagain	Avalanche: Sunburst	CNFAIC Staff
05/17/22	Turnagain	Observation: Tincan Ridge	Joe Kurtak
05/11/22	Turnagain	Avalanche: Cornbiscuit and Magnum west faces	CNFAIC Staff Forecaster
05/07/22	Turnagain	Observation: Granddaddy	Kit Barton
04/29/22	Turnagain	Observation: Sunburst wx station	AS/ MM/ AM/ NH
04/28/22	Turnagain	Observation: More Turnagain Pass/Summit Lake wet slab activity	Alex Marienthal
04/27/22	Turnagain	Observation: Magnum	Sykes / Buttrick Forecaster
04/27/22	Turnagain	Observation: Girdwood/Summit/Turnagain Road obs	A S

Riding Areas

Updated Wed, June 01st, 2022

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 as of May 1 per Forest Plan.
Placer River	Closed	Closed as of April 25th due to insufficient snow coverage.
Skookum Drainage	Closed	Closed as of April 1st per Forest Plan.
Turnagain Pass	Closed	Closed as of June 1st.
Twentymile	Closed	Closed as of April 6th due to insufficient snow coverage.
Seward District
Carter Lake	Closed	Closed as of May 1 per Forest Plan.
Lost Lake Trail	Closed	Closed as of May 1 per Forest Plan.
Primrose Trail	Closed	Closed as of May 1 per Forest Plan.
Resurrection Pass Trail	Closed	Closed as of May 1 per Forest Plan.
Snug Harbor	Closed	Closed as of May 1 per Forest Plan.
South Fork Snow River Corridor	Closed	Closed as of May 1 per Forest Plan.
Summit Lake	Closed	Closed as of May 1 per Forest Plan.