Fri, February 19, 2016 Turnagain Pass Avalanche Forecast

Fri, February 19th, 2016

Alpine
Above 2,500'

Moderate (2)

Treeline
1,000'-2,500'

Moderate (2)

Below Treeline
Below 1,000'

No Rating (0)

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

Cornice

Cornice

Cornice Fall is the release of an overhanging mass of snow that forms as the wind moves snow over a sharp terrain feature, such as a ridge, and deposits snow on the downwind (leeward) side. Cornices range in size from small wind drifts of soft snow to large overhangs of hard snow that are 30 feet (10 meters) or taller. They can break off the terrain suddenly and pull back onto the ridge top and catch people by surprise even on the flat ground above the slope. Even small cornices can have enough mass to be destructive and deadly. Cornice Fall can entrain loose surface snow or trigger slab avalanches.

More info at Avalanche.org

There has been no reports of human triggered avalanches since Monday. Overall temperatures have cooled throughout the week and winds were light yesterday. Observers have reported good stability and slope testers have been in steep terrain without incident. However, there have been a few large naturally cornice triggered avalanches in steep Alpine terrain. Avoid traveling on or underneath cornices. They may break much farther back than expected and could trigger a large avalanche on the slope below. Falling on to a slope with a refrigerator to school bus sized piece of snow would be bad news. There have been significant cornice cracks observed along ridgelines. You do not want to end up on the wrong side or take a dip into one of the wide ones on your snowmachine or skis.

In addition, watch for any lingering wind slabs on leeward slopes and loose snow sluffing. Both of these could be quite hazardous in steep, high consequence terrain.

As always practice safe travel techniques: ride slopes one at a time, park and regroup in safe areas, have escape routes planned and watch your partners.

Cornice crack on Magnum ridge. Photo: Amanda Goss

Avalanche Problem 2

Glide Avalanches

Glide Avalanches

Glide Avalanches are the release of the entire snow cover as a result of gliding over the ground. Glide avalanches can be composed of wet, moist, or almost entirely dry snow. They typically occur in very specific paths, where the slope is steep enough and the ground surface is relatively smooth. They are often proceeded by full depth cracks (glide cracks), though the time between the appearance of a crack and an avalanche can vary between seconds and months. Glide avalanches are unlikely to be triggered by a person, are nearly impossible to forecast, and thus pose a hazard that is extremely difficult to manage.

More info at Avalanche.org

Glide cracks continue to appear, grow and release throughout the Treeline (1000′-2500′) elevation band. They are on all aspects and are still totally unpredictable. The best way to minimize the risk is to avoid travel underneath. There was a new crack observed on Lipps yesterday in skiable terrain.

Glide crack in Main Bowl (1st Bowl). February 9th.

The same glide crack on February 18th.

Weather

Fri, February 19th, 2016

Yesterday was partly cloudy with light winds and temps in the mid 20Fs to low 30Fs.

Today will partly to mostly cloudy with a slight chance of snow showers during the day. Temperatures will be in the mid 20Fs to mid 30Fs and winds will be Easterly 5-15 mph. Clouds will increase overnight and with 1-4″ of snow possible as the first front affects the area.

Tomorrow snow showers and winds will increase as the next storm really moves into the region. The National Weather Service is decribing this as a robust front. Stay tuned for more details as the jury is still out on the timing, temperatures and the form of precipitation it will bring.

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

	Temp Avg (F)	Snow (in)	Water (in)	Snow Depth (in)
Center Ridge (1880′)	22	0	0	101
Summit Lake (1400′)	20	0	0	30
Alyeska Mid (1700′)	24	0	0	85

RIDGETOP 24-hour data (6am – 6am)

	Temp Avg (F)	Wind Dir	Wind Avg (mph)	Wind Gust (mph)
Sunburst (3812′)	22	E	5	13
Seattle Ridge (2400′)	23	n/a	n/a	n/a

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.