Mon, December 16, 2013 Turnagain Pass Avalanche Forecast

Mon, December 16th, 2013

Alpine
Above 2,500'

Moderate (2)

Treeline
1,000'-2,500'

Moderate (2)

Below Treeline
Below 1,000'

Moderate (2)

Alpine Above 2,500'		Moderate (2)
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

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

The storm that dropped 12-18” of new snow on Turnagain Pass came down with very little wind and relatively cold temperatures. The rate of loading was slow enough to not create widespread natural activity. Over time this new light density snow has formed into more cohesive slabs. Yesterday we received numerous reports of low volume slab activity around Turnagain Pass. All activity observed and reported yesterday ran on a crust that formed earlier in December.

The crust that exists below this new snow is fairly uniform in its distribution (i.e. is similar on all aspects and elevations). The new snow is also uniform in its distribution. The interface between this crust and new slab has shown poor bonding in many areas. As such, all aspects above and below treeline are harboring soft slabs that will continue to be sensitive to human triggers. Throw in the occasional pocket of buried surface hoar into the mix and it becomes trickier to figure out where the most sensitive areas are. Your best bet for avoiding this problem today is to stick to lower angled terrain.

Graham-Seattle 12-15-13

Soft slabs triggered remotely in steep terrain off of Seattle Ridge. (photo: Wagner)

Avalanche Problem 2

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

Loose snow avalanches will begin to come into play a bit more today with cold temperatures helping to weaken the snow surface. Expect sluffs to run slowly and be low volume. Pay attention to sluffs in steeper terrain where terrain traps are present. While the volume will be low the chances for injury will go up if you are knocked over and carried into trees, over rocks or into gullies.

Weather

Mon, December 16th, 2013

The mountains around Eastern Turnagain Arm picked up a trace of new snow in the past 24 hours. Winds have been light out of the Northwest and temperatures have averaged in the single digits F. Ridge top temperatures early this morning are hovering around 0 degrees F.

Clear and cold is in store today as a ridge of high pressure has built into the area. Winds will be light out of the North and Northwest.

Weather conditions will remain similar over the next several days. The next chance for precipitation looks to be late Wednesday into Thursday.

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.