Thu, April 18, 2013 Turnagain Pass Avalanche Forecast

Thu, April 18th, 2013

Alpine
Above 2,500'

Moderate (2)

Treeline
1,000'-2,500'

Low (1)

Below Treeline
Below 1,000'

Low (1)

Alpine Above 2,500'		Moderate (2)
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

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

The top 2 feet of our snowpack is where the issues can be found. Depending on aspect the sun has had significant effect to most slopes – either directly on the surface or by creating a series of now buried crusts.

In general, the better snow can be found on non-south aspects that get less sun exposure. Watch out for shallow slabs like the ones that we’ve been seeing recently. Check out the observations page for some examples of what to look out for.

The avalanches we’ve been seeing have followed a consistent pattern. Size has been low volume, but they run surprisingly far for the amount of snow involved. Most aspects are affected, with south having more of a crust/facet issue and north having more of a wind slab issue.

Picture is from last weekend on the south face of Sunburst.

Avalanche Problem 2

Dry Loose

Dry Loose

Dry Loose avalanches are the release of dry unconsolidated snow and typically occur within layers of soft snow near the surface of the snowpack. These avalanches start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-dry avalanches include point-release avalanches or sluffs.

More info at Avalanche.org

Shaded slopes still hold dry snow at higher elevations. Those areas are prone to loose snow sluffing by skier initiation. Just like the slab problem, the volume is relatively small but they can still travel good distances.

Additional Concern

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

Wet avalanche problems will start soon. The current pattern of cold overnight temperatures has kept it from becoming an issue, but it’s only a matter of time. As always this time of year – think about heat induced avalanche activity in the afternoon when the surface crust melts and the snowpack loses strength.

Weather

Thu, April 18th, 2013

Deja Vu.

Our stretch of sunny weather continues with freezing temperatures overnight and very little wind.

No snow or rain expected. Low temperature to 18 degrees, highs expected to reach the high 30s to low 40s at sea level. NE wind 0-10 mph, with some areas reaching higher speeds near Whittier and Seward.

The next advisory will be issued Saturday, April 20th.

Observations

Recent Observations for Turnagain Pass

Date	Region	Location	Observer
04/19/21	Turnagain	Avalanche: Triangle, Seattle creek	Will Morrison
04/18/21	Turnagain	Avalanche: Turnagain Pass Road Obs	Andy Moderow
04/18/21	Turnagain	Observation: Seattle Ridge, approximately 300 yards south of the up track	Brent Byrne
04/17/21	Turnagain	Avalanche: Road obs	Johnston-Bloom / Moderow Forecaster
04/16/21	Turnagain	Avalanche: Seattle Ridge	Wendy Wagner Forecaster
04/16/21	Turnagain	Avalanche: Turnagain Pass, non-motorized side seen from Seattle Ridge	CNFAIC Staff Forecaster
04/16/21	Turnagain	Observation: Sunburst	Lance breeding
04/15/21	Turnagain	Observation: Tincan	Schauer/ Rothman Forecaster
04/13/21	Turnagain	Observation: Turnagain Pass Road Obs	A Schauer Forecaster
04/12/21	Turnagain	Observation: Tincan	Johnston-Bloom / Latosuo Forecaster

Riding Areas

Updated Tue, April 20th, 2021

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	Open	No parking in turnaround at end of the road near the outhouse.
Placer River	Open	Please do not ride along Railroad tracks. Cross tracks at 90 degree angle and clear the right of way.
Skookum Drainage	Closed	The Skookum Valley is closed to snowmachines. This closure occurs annually on April 1 as per the CNF Forest Plan.
Turnagain Pass	Open
Twentymile	Closed
Seward District
Carter Lake	Open
Lost Lake Trail	Open
Primrose Trail	Open
Resurrection Pass Trail	Closed	Closed for the 2020/21 winter season.
Snug Harbor	Open
South Fork Snow River Corridor	Open
Summit Lake	Open