Fri, March 15, 2013 Turnagain Pass Avalanche Forecast

Fri, March 15th, 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

It is always good to remember what happened in the past. Three nights of calm, clear and cold weather earlier this week helped to form weak snow (surface hoar and facets) at the surface. That weak snow is now blanketed with a fresh coat of paint, and that paint will be easy to peel off today, especially above treeline. Wind slabs will be easiest to trigger today in upper elevation starting zones. These newly formed slabs are sitting on a variety of weak interfaces, including surface hoar on the northern half of the compass and weak faceted snow on the southern half. Look for these slabs to be in the 12″ range and be very sensitive to the weight of a person or sled. Slabs unaffected by wind will also be something to look out for and will be smaller, in the 6-8″ range. Today will be a good day to ratchet back your terrain choices, as those big lines that got hit on the last clear day now have the perfect slab/weak layer combination for avalanche activity.

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

This last batch of moisture that refreshed the snow surface ended with very light winds. This should make for excellent riding and skiing conditions but also make loose snow avalanches a problem to deal with. Volume should be in the low to moderate range and should be fast moving on steep shaded slopes in the higher elevations. Sun and warming will create the possibility of sluffs to be more damp on sunlit aspects through the day. Pay attention to loose snow moving downhill with you and move away from it, especially above terrain traps such as cliff bands, gullies and trees.

Additional Concern
Cornices
We have seen several very large cornices drop in the past few weeks. This problem is pretty simple to deal with; minimize your time near and especially below cornices, as they have the potential to do a lot of damage as evidenced last week in the Goldpan area on Turnagain Pass.

Weather

Fri, March 15th, 2013

In the past 24 hours the mountains around Turnagain Pass have picked up 6″ of new snow/.4″ of water with lesser amounts in the Girdwood Valley and south towards Summit Lake. Winds at the Sunburst station at 3,880′ have averaged 13mph out of the East with gusts to 45mph. Temperatures have remained cool with sea level stations staying in the mid 20s F and ridgetops in the teens.

Today expect periods of clear skies as we are between two weak low pressure systems. No precipitation is forecasted. Winds will be very light out of the East at 5mph and temperatures will be in the high 20s F at 1,000′.

The extended outlook calls for a mix of sun and clouds over the next several days with no precipitation expected.

_________________________________________________________________________________________

Kevin will issue the next advisory tomorrow morning, March 16th.

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 Sat, September 23rd, 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	Scheduled opening per Chugach National Forest plan December 1. Subject to adequate snow cover.
Placer River	Closed	Scheduled opening per Chugach National Forest plan December 1. Subject to adequate snow cover.
Skookum Drainage	Closed	Scheduled opening per Chugach National Forest plan December 1. Subject to adequate snow cover.
Turnagain Pass	Closed	Scheduled opening on the Wednesday before Thanksgiving per Chugach National Forest plan. Subject to adequate snow cover.
Twentymile	Closed	Scheduled opening per Chugach National Forest plan December 1. Subject to adequate snow cover.
Seward District
Carter Lake	Closed	Scheduled opening per Chugach National Forest plan December 1. Subject to adequate snow cover.
Lost Lake Trail	Closed	Scheduled opening per Chugach National Forest plan December 1. Subject to adequate snow cover.
Primrose Trail	Closed	Scheduled opening per Chugach National Forest plan December 1. Subject to adequate snow cover.
Resurrection Pass Trail	Closed	Scheduled opening per Chugach National Forest plan December 1. Subject to adequate snow cover.
Snug Harbor	Closed	Scheduled opening per Chugach National Forest plan December 1. Subject to adequate snow cover.
South Fork Snow River Corridor	Closed	Scheduled opening per Chugach National Forest plan December 1. Subject to adequate snow cover.
Summit Lake	Closed	Scheduled opening per Chugach National Forest plan December 1. Subject to adequate snow cover.