Sun, March 08, 2015 Turnagain Pass Avalanche Forecast

Sun, March 8th, 2015

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

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

Could we really see a hint of winter now that we are well into March? Now that we just switched over to Daylight Savings Time? Why not… It seems like all bets are off these days and we will take what we can get! Below are mid-elevation storm totals from a cold front that moved over Alaska Friday night through yesterday:

Turnagain Pass – 10″
Girdwood Valley – 8+”
Summit Lake – 3-6″
Hatcher Pass – 12-18″

WIND SLAB:
On the heels of this much anticipated new snow has been a cold Northwesterly wind. The winds produced plumes off some, but not all, peaks in the region yesterday afternoon and have continued to blow in the 15-20mph range overnight. This is prime speed for wind slab development and human triggered wind slab avalanches should be expected. Additionally, this flow direction is ideal for loading the East face of Seattle Ridge.

Yesterday, we were able to find and trigger a small wind slab just before the winds kicked up. Today, these types of avalanches should be a dime a dozen and easy to trigger. Slab depths are on the shallow side, 8-14″, yet could be stiff enough to support the weight of a person; this is concerning as the slab may allow someone on to it before breaking above them. The good news is, wind slabs should be easy to identify with their smooth rounded surface and upside down feel (harder snow over softer snow). Quick hand pits are a great way to see how the new snow is acting and I’d recommend a number of these as you move through the mountains.

Photo below is of an easily skier triggered soft wind slab yesterday on Sunburst’s Southwest face (3,000′ average depth 10″).

Winds transporting snow on Mount Alpenglow yesterday afternoon.

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

Watch your sluff. Sluffing in Friday/Saturday’s storm snow was prevalent yesterday and will be again today. These sluffs are entraining a significant amount of snow on sustained steep slopes and in channeled terrain. The cold temperatures will help to keep sluffs on the radar.

Weather

Sun, March 8th, 2015

It is very nice to finally have some new snow to report. Besides the storm totals above, see the chart below for the past 24-hour totals. The rain/snow line with this event hovered between 500 and 1,000′ and 3″ of wet snow (which has now frozen) fell at the parking lots at Turnagain. Snowfall shut down around noon yesterday and was followed by a switch in wind direction from the South to the Northwest. Cold air has and is currently being ushered in by the Northwesterly flow.

Today, visibility should be good with mostly sunny skies and a few lingering clouds. However, the cold Northwest winds are expected to remain in the 15-20mph range with higher gusts. Temperatures will continue to drop through the day into the teens at most locations, then to the single digits by tonight.

As we head into the early part of this week, no precipitation is expected as we will remain in a cold and blustery Northwest flow.

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

	Temp Avg (F)	Snow (in)	Water (in)	Snow Depth (in)
Center Ridge (1880′)	28	3	0.3	45
Summit Lake (1400′)	29	2	0.3	8
Alyeska Mid (1700′)	30	2	0.27	29

RIDGETOP 24-hour data (6am – 6am)

	Temp Avg (F)	Wind Dir	Wind Avg (mph)	Wind Gust (mph)
Sunburst (3812′)	20	W	12	43
Seattle Ridge (2400′)	23	n/a	13	42

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.