Thu, April 11, 2013 Turnagain Pass Avalanche Forecast

Thu, April 11th, 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

Despite the light winds the past couple days, shallow and very sensitive slabs have been able to form in scattered areas along ridgelines (shown in the photo below). This is mainly due to the weekend’s snow being so light and easy to transport. They didn’t pack much punch yesterday but a bump in wind overnight with plenty of low density snow available for transport will likely have continued wind slab development. Watch for these to be 6-10″ thick and on a variety of aspects – winds have been blowing from various directions due to our region being in the heart of a low pressure system. Keeping an eye on the snow texture as well as for shooting cracks from your skies/board or sled will be key.

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 are expected to be prevalent again today. These are both in the dry snow category and the wet/damp snow category (pending clear skies):

Dry snow: The very cold overnight temperatures will add to the looseness of the surface snow (and to the good riding/skiing conditions). This should keep dry sluffs something to plan for on steep slopes.

Wet/damp snow: If the skies remain clear today, the sun should have ample time to warm southerly aspects. Watch for dampening of the snow surface to turn a small low volume dry sluff into a larger heavier damp sluff. Shallow slabs are also possible with daytime warming on southerly aspects. These sluffs and slabs have the potential to release naturally if we do get intense sunshine today.

Weather

Thu, April 11th, 2013

Under mostly clear skies this morning, temperatures have plummeted to the single and minus single digits. Winds have remained light from the north and west with a slight bump overnight to the 15-20 mph range. Yesterday, mostly cloudy skies limited much daytime heating and 24-hour average temperature at the Sunburst wx station was +1F while winds averaged 4mph with gusts to 16.

Today, a few clouds are likely to stream through but the sun should have time to warm things up a bit. Temperatures should reach the mid 20’sF at sea level up to treeline and the low teens on the ridgetops. Winds will be light and slowly backing to the SE where they look to pick up tonight to the 15mph range.

Beautiful spring weather consisting of sunny days, cold nights and light to moderate northerly winds are on tap for the remainder of the week and into the weekend.

Kevin will issue the next advisory tomorrow, April 12th.

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.