Mon, December 07, 2015 Turnagain Pass Avalanche Forecast

Mon, December 7th, 2015

Alpine
Above 2,500'

Low (1)

Treeline
1,000'-2,500'

Low (1)

Below Treeline
Below 1,000'

Low (1)

Alpine Above 2,500'		Low (1)
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

Normal Caution

Normal Caution

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

More info at Avalanche.org

As our extended period of clear weather continues, we are sitting in the “normal caution” phase of avalanche issues. These include:

1- Sluffs on steep slopes. These have been small to medium in volume, but are getting larger by the day as the surface becomes weaker under clear skies.

2- Triggering an outlier avalanche. This would most likely be an ‘unsupported slab’ that sits above a cliff or steep rocky terrain. Check out video HERE for an example.

3- Triggering a cornice fall. The cornices maybe be small(ish) right now, but they are clearly large enough to take you down somewhere you don’t want to go. As always, give them a wide berth.

Photo: You can see the boot pack to the top of Tincan Proper steers clear of the cornices, however it looks as if someone may have triggered a piece of cornice recently from the boot pack, or possibly veering off of it. A good reminder for us to err of the side of caution when traveling near cornices.

Additional Concern

Persistent Slabs

Persistent Slabs

Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.

More info at Avalanche.org

Below is a glimpse of the high elevation snowpack (3,700′). We are finding the old faceted snow from the mid-November cold snap being compressed below roughly 1-3′ of dense and hard Thanksgiving snow. Other than Graham’s pit on Friday, we have seen no reactivity in these old facetd. This includes both snowpack stability tests as well as a large number of folks testing the slopes in the region.

“No results” mentioned in pit = a stabilized snowpack.

As we may be approaching the end of our clear spell, we are watching for the next possible weak layer(s) develop – the surface. Check out the recent reports for more on this HERE.

Weather

Mon, December 7th, 2015

Yesterday was another stunning day in the backcountry; sunny skies, calm winds and temperatures in the mid 20’s F. This was all above the fog and inversion. However, down along the road corridor, temperatures in the single digits existed along with valley fog extending up to 1,500′.

Today (and tomorrow) will be much the same, mostly clear skies with valley fog. Winds should remain light and variable yet are forecast to increase from the East tonight to the 10-15mph range. Temperatures will again be in the mid 20’s F on the ridgetops and in the single digits in the parking lots – that’s quite an inversion.

Our next shot for snow looks to be Thursday or Friday. Stay tuned!

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

	Temp Avg (F)	Snow (in)	Water (in)	Snow Depth (in)
Center Ridge (1880′)	17	0	0	24
Summit Lake (1400′)	5	0	0	11
Alyeska Mid (1700′)	17	0	0	14

RIDGETOP 24-hour data (6am – 6am)

	Temp Avg (F)	Wind Dir	Wind Avg (mph)	Wind Gust (mph)
Sunburst (3812′)	26	E	2	10
Seattle Ridge (2400′)	19	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 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.