Tue, November 28, 2017 Turnagain Pass Avalanche Forecast

Tue, November 28th, 2017

Alpine
Above 2,500'

Moderate (2)

Treeline
1,000'-2,500'

Moderate (2)

Below Treeline
Below 1,000'

Moderate (2)

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

Danger Scale:

No Rating (0)

Low (1)

Moderate (2)

Considerable (3)

High (4)

Extreme (5)

Avalanche Problem 1

Storm Slabs

Storm Slabs

Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-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

The advisory area received a few inches of additional snow in the last 24 hours and more is on tap today and tonight. Temperatures have risen and the snowline is forecasted to rise to 1000′. Precipitation that falls today and tonight will be heavier/wetter than yesterday. Warm, wet snow over cold dry snow may form storm slabs. New snow combined with easterly winds gusting into the 40s will add to the potential for wind slabs on leeward slopes. Steep (35+ degrees) unsupported slopes will be the most suspect for triggering new or old wind slabs. If you do venture out today it will be important to pay attention to drifting, look for cracking and listen for hollow sounds and/or whumpfing.

Determining whether or not new snow is bonding to old snow surfaces will be the question in the next few days. Remember this snow is falling on variety of surfaces including crust, facets, old wind effected snow or grass and rocks. Getting pulled down by even a small slab could have a very rough ride due to rocks and thin snow cover.

If rain falls on the new snow in Portage Valley wet loose avalanches will be possible in ice climbing terrain.

Image of the melt freeze crust covering most of the terrain above approximately 1600′. The main concern is where the crust is underneath weak faceted snow that will be covered up in the next few days. The weak faceted snow is our greatest concern for future snow load as it will likely inhibit the new snow from bonding and the crust could be a slippery bed surface.

Weather

Tue, November 28th, 2017

Yesterday light snow fell in the morning and tapered off in the afternoon. Turnagain picked up a few inches and Girdwood added another inch to what had fallen overnight. Temperatures rose to above freezing at Center Ridge, 1880′ on Turnagain Pass. Winds were easterly gusting into the 40s.

Today will be cloudy with another 1-4 inches of snow forecasted to fall with a chance of rain up to at least 1000′. Winds will be easterly again 10-20mph gusting into the 40s. Expect temperatures in the mid 20Fs at upper elevations to mid 30Fs at sea level. Tonight precipitation will increase, 4-8 inches of snow possible with rain/snow mix at low elevations, and the easterly winds will continue with gusts bumping into the 50s.

Tomorrow rain/snow showers will continue and winds should decrease in the afternoon. Temperatures will stay warm until the evening as this system moves out of the area.

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

	Temp Avg (F)	Snow (in)	Water (in)	Snow Depth (in)
Center Ridge (1880′)	33	3	.3	12
Summit Lake (1400′)	29	1	.1	7
Alyeska Mid (1700′)	31	1	.1	7

RIDGETOP 24-hour data (6am – 6am)

	Temp Avg (F)	Wind Dir	Wind Avg (mph)	Wind Gust (mph)
Sunburst (3812′)	22	ENE	18	45
Seattle Ridge (2400′)	25	Sensor Rimed	Sensor Rimed	Sensor Rimed

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 Mon, May 15th, 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	Open	Chugach NF staff will be assessing daily after May 15th. Please keep machines on the snow and avoid brown spots to keep this area open as long as possible.
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.