Wed, January 07, 2015 Turnagain Pass Avalanche Forecast

Wed, January 7th, 2015

Alpine
Above 2,500'

Moderate (2)

Treeline
1,000'-2,500'

Low (1)

Below Treeline
Below 1,000'

No Rating (0)

Alpine Above 2,500'		Moderate (2)
Treeline 1,000'-2,500'		Low (1)
Below Treeline Below 1,000'		No Rating (0)

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

A large wind event last week has left the slopes scoured on ridges with hard-pack snow conditions above 2500’. This densely settled snow combined with time has added to the strength of the slab by making it supportable and difficult to trigger a buried weak layer below. In general normal caution is advised with the exception of very steep slopes.

Some uncertainty still exists in terrain steeper than 40° and where the snowpack is thinner. The current structure of the snowpack is a 1-3’ slab sitting on a weak layer, and there remains some potential on specific features for a slab to propagate. Avoid shallow areas of the snowpack, especially near rocks and steep convex rollovers.

In places like Girdwood and Summit Lake where the snowpack is thinner– triggering a layer of buried surface hoar or facets could be more likely. In these areas consider keeping your slope angles even lower.

If you choose to ski a steep slope identify features of concern and the consequences below you. Practice safe travel techniques like exposing one person at time, communicating route decisions, and always be aware of groups above and below you.

Over the last week new surface hoar growth has been widely documented and something to be aware of heading into our next warm storm cycle. A big thanks to everyone submitting observations this winter!

Surface hoar formation this week at 2000' in the Girdwood Valley

Photo Credit: Kyle Bates

Weather

Wed, January 7th, 2015

Over the last few days skies have been clear and an inversion has brought single digit F temps to valley floors with ridgetops in the mid 20’s F. Overnight Eastern winds have been light with no new precipitation.

Temperatures are expected to increase into the low 30’s F today as a low-pressure system approaches from Southeast Alaska. Winds will be out of the East 10-20mph. We may see a trace of new snow tonight, but it is more likely to be in the form of freezing rain at sea level.

Overnight and into tomorrow warm air will continue to override the cool surface air in Southcentral Alaska increasing the likelihood of freezing rain at lower elevations. Temps could be as high as the mid 30’s F at sea level with lows in the 20’s F at ridgetops. Winds are expected to be moderate from the East.

It is uncertain how much precipitation this warm air mass could bring, but it looks like lower elevation temperatures will remain warm (mid-high 30’s F) into the weekend.

PRECIPITATION 24-hour data (6am – 6am)

	Temp Avg (F)	Snow (in)	Water (in)	Snow Depth (in)
Center Ridge (1880′)	24	0	0	33
Summit Lake (1400′)	12	0	0	6
Alyeska Mid (1700′)	22	0	0	25

RIDGETOP 24-hour data (6am – 6am)

	Temp Avg (F)	Wind Dir	Wind Avg (mph)	Wind Gust (mph)
Sunburst (3812′)	23	E	7	30
Seattle Ridge (2400′)	23	Var	8	29

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.