Wed, January 28, 2015 Turnagain Pass Avalanche Forecast

Wed, January 28th, 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

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

Temperatures have been relatively cool (single digits to teens F) over the last four days. Turnagain Pass has about 4-6” of slightly aged, low-density snow available for transport. This morning winds have increased along ridgetops averaging 15mph with gusts into the low 30’s. The prominent wind direction on Seattle Ridge has been Southwesterly and Easterly on Sunburst. If winds continue as forecasted today this combination of loose dry snow and moderate winds could be just enough to form wind slab pockets up to 6” thick. Be on the look out for tender areas of wind-stiffened snow. These shallow slabs will be small, not likely to bury a person, but could be just enough to knock you off your feet and take you for a ride in terrain steeper than 35°.

Yesterday we received a report of a skier triggered soft slab 10” deep that propagated 75’ across a Western aspect, mid-slope near 5000’. This is outside of our normal forecast zone, but is worth noting for anyone planning to access remote terrain. Also Girdwood Valley, Portage, and Summit Lake have seen more wind exposure than Turnagain Pass in the last three days, therefore wind slab pockets could be more tender and easier to initiate on leeward features. Evaluate surface conditions as you travel today and watch for visible wind loading on terrain above you. This could be extra important for ice climbers in very steep terrain where natural wind slab avalanches could occur.

Additional Concern

Normal Caution

Normal Caution

Normal Caution means triggering an avalanche is unlikely but not impossible.

More info at Avalanche.org

Glide Cracks

No new significant glide activity has been observed over the last week. Due to the unpredictable nature of glide avalanches it is important to get a good look at the terrain you’re about to ski/ride to avoid traveling directly on the slab of a glide. See photo below. In general be quick if traversing direcly below glides to minimize your travel time in the run-out zone.

Close up of a glide crack on Magnum’s South face. This ski track crosses directly over this glide and appears to be from before Jan.24th with 2″ of new snow covering it.

Low snow coverage

Below 2000’ low snow coverage is deceiving with only a few inches of new snow covering rocks, ice and vegetation. Take your time getting in and out of the alpine today.

Weather

Wed, January 28th, 2015

Yesterday skies were sunny and clear with light variable winds averaging 5-10mph. No new precipitation was recorded and temperatures increased slightly from single digits into the mid teens to low 20’sF during the day.

Overnight ridgetop winds have increased, averaging 15mph with gusts into the low 30’s. Wind directions are variable based on location. As of this morning Sunburst wind direction is Easterly, and Seattle Ridge has more of a Southwesterly flow. Temperatures have remained in the teens (F) overnight and no precipitation has been recorded.

Today ridgetop winds are expected to remain moderate, averaging 15mph with gusts into the high 20’s to low 30’s from the Northeast. Temps will be in the low to mid 20’s F, with partly cloudy skies.

Tonight there is a chance for light precipitation, up to an 2 € of new snow at higher elevations and 1 € at sea level. Temperatures are expected to remain in the low to mid 20’s F and winds will remain moderate 15-25mph, mostly from the Northeast into the evening.

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

	Temp Avg (F)	Snow (in)	Water (in)	Snow Depth (in)
Center Ridge (1880′)	19	0	0	31
Summit Lake (1400′)	13	0	0	7
Alyeska Mid (1700′)	16	0	0	22

RIDGETOP 24-hour data (6am – 6am)

	Temp Avg (F)	Wind Dir	Wind Avg (mph)	Wind Gust (mph)
Sunburst (3812′)	16	E	6	25
Seattle Ridge (2400′)	17	Var	9	33

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.