Tue, April 09, 2013 Turnagain Pass Avalanche Forecast

Tue, April 9th, 2013

Alpine
Above 2,500'

Moderate (2)

Treeline
1,000'-2,500'

Moderate (2)

Below Treeline
Below 1,000'

Moderate (2)

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

Danger Scale:

No Rating (0)

Low (1)

Moderate (2)

Considerable (3)

High (4)

Extreme (5)

Avalanche Problem 1

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

I suppose if it’s not going to be full on spring, it might as well be full on winter. Yesterday’s snow (and possibly another inch or two today) should help refresh and fill in many of the old tracks. Some of us were hoping for a bit more in this neck of the woods but we’ll take it nonetheless.

Today, loose snow avalanches should be easy to initiate. These sluffs will likely run far and fast as they will be sliding on hard surfaces underneath – predominantly on south, west and east aspects. On steeper more sustained slopes they could entrain significant amounts of snow so plan accordingly.

Avalanche Problem 2

Wind Slabs

Wind Slabs

Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind 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

Though winds have been light, so is the snow. It will not take much to move the new snow and deposit it into soft slabs. These should be fairly touchy if you find one and around a foot deep. They are likely confined to the upper elevations and on most aspects due to the changing wind directions. Watching for cracking in the snow around you and feeling for stiffer snow over softer snow will be good clues to suss out any wind slabs.

Additional concerns:

Sun: Keep a close eye out for when the sun makes its first appearance. Solar heating will quickly destabilize the new snow and sun induced point releases and shallow slab avalanches could be fairly widespread. This may not occur for a couple days but it looks like there is a small chance skies could break this afternoon.

Weather

Tue, April 9th, 2013

The big snow event that is hitting Anchorage and Hatcher Pass is leaving the Eastern Turnagain Arm a bit high and dry. Snowfall has tapered off this morning but, we have squeaked out several inches of very low density snow – and may pick up another inch or two today. Storm totals at the precip stations around the Arm since 6AM yesterday are:
Turnagain Pass SNOTEL (1900′): 4″ snow – .3″ water eq.
Alyeska Mid Mt (1700′): 7″ snow – .45 water eq.
Summit Lake SNOTEL (1400′): 2″ snow – .1 water eq.

The two SNOTEL sites typically under-represent snowfall when it’s this light. So, we are likely looking closer to 6-8″ on Turnagain Pass and 3-4″ in the Summit area.

Winds associated with the snowfall began light out the east and have shifted around to the NW overnight where they are averaging 5mph with gusts to 10mph. The NW flow is bringing is very cold air and temperatures are currently in the single digits on the ridgelines and the low teens at 1,000′.

Today we can expect lingering snow showers to add another inch or two. Temperatures will be in the 10-15F range above treeline and 15-20F below treeline. Winds look to be light out of the NW (5mph gusting 10mph).

The cold air and scattered snow showers look to remain in place through Thursday.

Kevin will issue the next advisory tomorrow morning, April 10th.

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.