Tue, December 08, 2015 Turnagain Pass Avalanche Forecast

Tue, December 8th, 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

The Turnagain Pass area saw another sunny day with moderate temperatures and no reports of significant instability. An observation from Saturday illustrates the potential for small slabs in steep areas, a typical LOW danger concern.

As the weather pattern shifts today, bringing showery weather and stronger winds, taking inventory of the surface characteristics is critical to get a picture of what may happen in the days to come as the conditions change. We know that any new precipitation will land on a combination of weak faceted snow and surface hoar that have formed over the past days during the cold clear weather. Underneath these persistent grain types, that could become persistent weak layers, is either a stout rain crust (up to around 2500′) or dense snow that could act as a future bed surface. A forecaster observation from Sunday speaks to what to keep in mind when thinking about near surface facets and surface hoar together.

***If winds increase today and snow is moved around pay attention to areas that are leeward and may develop small pockets of wind slab on the weak snow/bed surface combination.

Remember the surface conditions (facets and surface hoar to ridge tops) that may get buried this week.

Avalanche Problem 2

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

We are continuing to track the layer of basal facets from the cold period in early November. For the most part these have been non-reactive. With the potential for additional load in the coming week we will be interested to see if this changes.

Weather

Tue, December 8th, 2015

Today’s weather is forecasted to be a mixture of showery weather in the morning and then mostly to partly cloudy in the afternoon. There is the possibility of snow with up to an inch of accumulation. Temperatures will be in the upper 20Fs to mid 30Fs. Wind will be N-NE, 10-20 mph with gusts in the 30s.

Tomorrow the unsettled weather will continue as the low in the Gulf spins moisture into the region. Cloudy skies, snow showers and warmer temperatures are on tap for the week as the overall pattern shifts.

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

	Temp Avg (F)	Snow (in)	Water (in)	Snow Depth (in)
Center Ridge (1880′)	22	0	0	23
Summit Lake (1400′)	15	0	0	11
Alyeska Mid (1700′)	25	0	0	19

RIDGETOP 24-hour data (6am – 6am)

	Temp Avg (F)	Wind Dir	Wind Avg (mph)	Wind Gust (mph)
Sunburst (3812′)	22	NE	18	38
Seattle Ridge (2400′)	22	SE	15	38

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.