Sat, December 07, 2013 Turnagain Pass Avalanche Forecast

Sat, December 7th, 2013

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

More info at Avalanche.org

Conditions right now are odd for December in Alaska. Total snow depth is only 15-30 inches, barely enough to justify putting boards on your feet. Exposed rocks and trees continue to be the primary backcountry hazard.

In some ways the snowpack is showing characteristics of typical Spring conditions with point release avalanches possible in the warmer and higher elevation areas. Unlike springtime, the wet/loose activity is entraining weaker faceted snow and volume is severely limited by the shallow snowpack. The freezing rain and temperature inversion started forming an ice crust a couple days ago, but in areas where temperatures have been above freezing for 24 hours, the crust has given way to soft and wetter snow.

This combination is allowing for low volume wet/loose avalanches that can travel at slow speeds for a reasonable distance if the slope is steep enough. Probably nothing to be afraid of, but something to watch for, and definitely atypical for December. Point release activity like this has been seen around Summit Lake and in the Girdwood valley.

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 got a report this morning of significant avalanche debris in the Portage valley near a popular ice climb, fresh in the last couple days. This is a great reminder that specific terrain features can harbor problems, especially when you are dealing with big, steep terrain and finicky weather in places like Portage.

Avalanches like this are the main reason why we don’t believe our avalanche advisory for Turnagain Pass is a good indicator for Portage, Whittier, or the heavily glaciated regions closer to Prince William Sound.

Weather

Sat, December 7th, 2013

Rain was falling across our region on Thursday. That trend dried out yesterday, but temperatures have been above freezing for most of the last 24 hours at all elevations.

This morning we can see a temperature inversion again. Sea level temperatures are cooling off and dipping below freezing. Ridge top temperatures are still in the upper 30s, the rain/snow line is predicted at 5600ft today. Wind is light from the northwest.

Looking into the future, a cooling trend is expected. No major snowfall is in the forecast. This means we can expect a stout melt/freeze crust to firm up this week.

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.