Mon, January 09, 2017 Turnagain Pass Avalanche Forecast

Mon, January 9th, 2017

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 sunny skies and calm weather remains over the area, the snowpack continues to adjust to the impacts of the high winds last week. It has now been 11 days since the last snowfall. Although we are still finding poor structure on slopes above the trees that have not avalanched, the slab continues to lose its reactivity in pits and there has not been a human triggered avalanche for a week. There are several weak layers sitting under the old hard wind slabs; these are facets and buried surface hoar in the mid-pack and facets at the base of the pack. Check out the video below for a look at a suspect trigger point (thin rocky area on an unsupported slope) from yesterday.

The one change in weather today is the warming at the upper elevations. Check out the graph below of the Sunburst weather station at 3,812′ that hit 39F this morning! Will this be enough warming to impact the surface conditions, or the slab? Likely not too much since the atmosphere is so dry and skies are clear (allowing the snowpack to radiate its warmth back into space).

Surface conditions? Riding and skiing has been reported to be nice, yet bottomless, in areas below treeline in soft ‘recycled’ powder. Above treeline, surface conditions are variable: wind affected hard/old slabs, anti tracks, sastrugi, breakable wind crust, and in some areas, interspersed with soft old faceted snow.

As always, keep a lookout for whumphing and cracking in the snow. These are signs you found a slab that remains unstable and again a good reason to keep up safe travel protocol (expose one person at a time, group up in safe zones and have an escape route planned).

Pastoral Peak: Fairly well distributed grains of shale and dirt covering the Pastoral Glacier; an indication of how strong the winds were during the Dec 29 and Jan 5th wind events. (Photo: S. Galoob & J. Haffener)

Additional Concern

Glide Avalanches

Glide Avalanches

Glide Avalanches are the release of the entire snow cover as a result of gliding over the ground. Glide avalanches can be composed of wet, moist, or almost entirely dry snow. They typically occur in very specific paths, where the slope is steep enough and the ground surface is relatively smooth. They are often proceeded by full depth cracks (glide cracks), though the time between the appearance of a crack and an avalanche can vary between seconds and months. Glide avalanches are unlikely to be triggered by a person, are nearly impossible to forecast, and thus pose a hazard that is extremely difficult to manage.

More info at Avalanche.org

Glide avalanches are possible this week: The warm temperatures at the upper elevations may enhance ‘glide’ in the snowpack. Watch for glide cracks to open up and a few may release. This pattern is similar to last week when 3 glide cracks released. Known cracks exist on the South face of Eddie’s, Goldpan (behind the Magnum ridge), East face of Seattle Ridge (Northern end) and Southerly slopes near Johnson Pass.

Glide avalanche in Lynx creek from January 2nd

Weather

Mon, January 9th, 2017

Sunny skies – calm winds and an impressive inversion is over the region! Yesterday we saw temperatures in valley bottoms between -5 and 5F where at the 3,500′ ridgelines it was 35F (balmy). Winds were light and variable.

Today, upper elevation temperatures will be even warmer – overnight Sunburst weather station reports temperatures rising to 39F. Valley bottoms will remain cold, in the single digits, and ridgetops in the mid 30’sF. Winds are forecast to be 5-10mph from a Northerly direction and skies clear.

This pattern looks to persist through the week – but….. models are showing the blocking high pressure eroding by the end of the week and chance for precipitation this weekend.

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

	Temp Avg (F)	Snow (in)	Water (in)	Snow Depth (in)
Center Ridge (1880′)	19	0	0	34
Summit Lake (1400′)	7	0	0	11
Alyeska Mid (1700′)	21	0	0	22

RIDGETOP 24-hour data (6am – 6am)

	Temp Avg (F)	Wind Dir	Wind Avg (mph)	Wind Gust (mph)
Sunburst (3812′)	35	NE	4	14
Seattle Ridge (2400′)	32	N	3	8

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.