Wed, January 29, 2014 Turnagain Pass Avalanche Forecast

Wed, January 29th, 2014

Alpine
Above 2,500'

Considerable (3)

Treeline
1,000'-2,500'

Considerable (3)

Below Treeline
Below 1,000'

Considerable (3)

Alpine Above 2,500'		Considerable (3)
Treeline 1,000'-2,500'		Considerable (3)
Below Treeline Below 1,000'		Considerable (3)

Danger Scale:

No Rating (0)

Low (1)

Moderate (2)

Considerable (3)

High (4)

Extreme (5)

Avalanche Problem 1

Wet Loose

Wet Loose

Wet Loose avalanches are the release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry Avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.

More info at Avalanche.org

Without any reported natural avalanche activity again yesterday we have reason to believe that after a solid 12 days of rain and unseasonably warm temperatures the snowpack is adapting to this new normal. Natural avalanches will be less likely today but given the results from DOT and AKRR avalanche mitigation work along the Seward Highway yesterday, the faceted layer at the bottom of the snowpack is still proving to be quite reactive given the right (or large enough) trigger.

We still need several days and nights in a row with below freezing temperatures to really lock up the snowpack in these mid-elevations (1800’ – 3500’) where the vast majority of avalanche activity has occurred during this warm-up.

Below 1800’ our snowpack has literally deflated, losing perhaps 75% or more of its mass since January 15^th due to rain and unseasonably warm temperatures. When travelling through this elevation band, avoid avalanche runout zones such as funneled terrain.

Peterson Creek path @ MP 84. Helicopter bombing triggered wet slab avalanche running on basal facets. Debris ran all the way to sea level even though the snow line is at approximately 1,000′.

Photo: Kevin Wright

Avalanche Problem 2

Deep Persistent Slabs

Deep Persistent Slabs

Deep Persistent Slab avalanches are the release of a thick cohesive layer of hard snow (a slab), when the bond breaks between the slab and an underlying persistent weak layer deep in the snowpack. The most common persistent weak layers involved in deep, persistent slabs are depth hoar or facets surrounding a deeply buried crust. Deep Persistent Slabs are typically hard to trigger, are very destructive and dangerous due to the large mass of snow involved, and can persist for months once developed. They are often triggered from areas where the snow is shallow and weak, and are particularly difficult to forecast for and manage.

More info at Avalanche.org

Broken skies yesterday gave us a few brief glimpses of the high peaks around the Girdwood Valley. From the binoculars, winter appears to exist at these upper elevations (above about 4,000’) where the snow surface appears thick and plastered onto steep terrain in true Chugach fashion. With evidence of a deep slab avalanche cycle over the weekend there is still reason to be suspect of high elevation terrain as the deep slab problem is not one to heal itself quickly. If travelling into these upper elevations pay attention to what’s above you, including looming cornices which if released can act as a trigger large enough to initiate an avalanche.

Weather

Wed, January 29th, 2014

Over the last 24 hours temperatures have continued a slow and steady decline at ridgetop locations with both Seattle Ridge and Sunburst maintaining temperatures below 32 degrees. Temps at sea level remained above average in the low to mid- 40’s. Winds continued out of the east averaging around 20mph. Precipitation was pretty limited with just a trace of rain and snow falling throughout the day. Rain/ snow line was around 2,000′ yesterday.

Temperatures today look to be in the mid-30’s at 1,000′ cooling to mid to low 20’s at ridgetop locations. We may see just a trace of precipitation today (with snow falling around 1,000′) as the current low pressure weakens and moves through our area. Winds will continue from the southeast in the 17-31mph range.

The trend for overnight and into tomorrow appears to be a building high pressure which should dry us out for a day or two though temperatures do not appear to drop dramatically.

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.