Thu, January 23, 2014 Turnagain Pass Avalanche Forecast

Thu, January 23rd, 2014

Alpine
Above 2,500'

High (4)

Treeline
1,000'-2,500'

High (4)

Below Treeline
Below 1,000'

High (4)

Alpine Above 2,500'		High (4)
Treeline 1,000'-2,500'		High (4)
Below Treeline Below 1,000'		High (4)

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

We continue to see new wet avalanche activity. The big new one was on the west face of Cornbiscuit. The lower part of the upper face pulled out full depth sometime between Tuesday night and Wednesday morning. This area is above treeline but well within the zone that is getting rain. See photo below.

As long as temperatures remain above freezing and especially during active rainfall, wet slab avalanches are possible and can be quite dangerous.

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

Deep slab continues to be a concern as the upper elevations have stress added. The equation here is simple – known reactive weak layers are getting heavy additional loading day after day. These weak layers can cause large widespread avalanches anywhere from 4-7 feet deep and pull all the snow to the ground. This problem is also worse during periods of precipitation, but will linger even after the storm ends.

Steep upper elevation terrain should be avoided, especially during periods of intense precipitation.

Additional Concern

Storm Slabs

Storm Slabs

Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.

More info at Avalanche.org

Up in the higher elevations there is enough storm snow and wind loading to have problems in the recent layers. Think about wind slabs and storm slabs 1-3 feet in depth. If an avalanche is started in these layers it could possibly step down into deeper layers. I will be surprised if anybody actually makes it above the rain line today.

Weather

Thu, January 23rd, 2014

A steady jet of moisture is coming from subtropical latitudes, straight north to southcentral Alaska. This pattern is expected to persist through Friday night. According to the National Weather Service, the Eastern Kenai peninsula could get another 3-6 inches of rain through Friday afternoon. Freezing levels will also increase to 4000-6000 feet elevation.

Today looks like the warmest yet. Rain will continue, transitioning to snow around 2400 feet. Wind at the ridge tops – Southeast 28-40 mph.

The first sign of a break from this pattern is on Saturday, with a chance of partly sunny skies.

Observations

Recent Observations for Turnagain Pass

Date	Region	Location	Observer
05/06/20	Turnagain	Avalanche: Pastoral Peak, north face	Andy Duenow
04/10/20	Turnagain	Avalanche: Wolverine	Mike Records
04/10/20	Turnagain	Observation: Eddies lookers right shoulder	Matt Yoder
04/09/20	Turnagain	Observation: Bench Peak	Mike Records
04/04/20	Turnagain	Observation: Tincan	Anonymous
04/04/20	Turnagain	Observation: Pete’s North	Anonymous
03/26/20	Turnagain	Avalanche: Tincan – Proper (SW facing)	CNFAIC Staff
03/26/20	Turnagain	Avalanche: Seattle Ridge	W Wagner Forecaster
03/25/20	Turnagain	Avalanche: Sunburst Uptrack @ 2000′	J. Boisvert
03/24/20	Turnagain	Observation: Turnagain – Road Observations	W Wagner Forecaster

Riding Areas

Updated Fri, May 01st, 2020

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
Placer River	Closed
Skookum Drainage	Closed
Turnagain Pass	Closed	Closed as of May 1. Thanks for a fun, safe season!
Twentymile	Closed
Seward District
Carter Lake	Closed
Lost Lake Trail	Closed
Primrose Trail	Closed
Resurrection Pass Trail	Closed
Snug Harbor	Closed
South Fork Snow River Corridor	Closed
Summit Lake	Closed