Sat, March 30, 2013 Turnagain Pass Avalanche Forecast

Sat, March 30th, 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

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

Nearly all the activity we’ve seen recently can be classified under wind slab. Fortunately everything we’ve seen has been low volume and isolated to small pockets. The photo below is from 2 days ago on Tincan.

Since we just got a significant additional load of new snow and wind, this concern is worse today. Snowfall was heavy enough yesterday to limit visibility and prevent anybody from getting above treeline. We haven’t seen firsthand the areas of highest concern, but we know it’s been snowing and blowing.

South facing slopes will add another layer of complexity. Multiple layers of buried sun crusts can be found on sunny aspects. We don’t know how those layers will react to the moderate additional snow load, but it’s worth considering that new snow doesn’t bond easily to slippery crusts. Stability aside, those crust layers may affect the quality of skiing and riding on south aspects.

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

In areas that were not wind affected we can expect loose snow to sluff easily in steep terrain. Anywhere the wind didn’t stiffen up the surface and slope angles exceed the mid 30 degrees you should expect snow to sluff and entrain volume on the way down. This could be a problem if surprised or in steep channeled terrain.

Weather

Sat, March 30th, 2013

Snow totals for the last 24 hours

Turnagain Pass snotel – 8 inches

Alyeska midway – 10 inches

Summit lake mountains – 6 inches

Wind has been trending from the southeast in Turnagain Pass with variations depending on the location. Temperatures are warmer than they’ve been, producing mixed rain and snow at sea level. Above 1500 feet the snow is dry.

Today’s weather calls for scattered snow showers. The bulk of the precipitation has passed. Expect a slight cooling trend and a diminishing trend with the wind.

Wendy will issue the next advisory tomorrow morning, March 31st.

Observations

Recent Observations for Turnagain Pass

Date	Region	Location	Observer
01/31/23	Turnagain	Observation: Johnson Pass area	Megan Guinn / W Wagner Forecaster
01/29/23	Turnagain	Observation: Tincan Backdoor	AAS-Level 1 1/27-1/30
01/28/23	Turnagain	Observation: Sunburst	Brooke Edwards
01/28/23	Turnagain	Avalanche: Seattle Ridge	W Wagner
01/28/23	Turnagain	Observation: Tincan Common	Tony Naciuk
01/27/23	Turnagain	Observation: Sunburst	John Sykes
01/27/23	Turnagain	Avalanche: Lynx Creek	Megan Guinn / W Wagner
01/25/23	Turnagain	Observation: Cornbiscuit	John Sykes Forecaster
01/22/23	Turnagain	Avalanche: Tincan	Schauer/ Guinn
01/21/23	Turnagain	Avalanche: Seattle Ridge	Elias Holt

Riding Areas

Updated Fri, January 06th, 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	Open	Opened Dec 13th.
Placer River	Closed	Closed Jan 5th due to lack of snow (holiday storms rained away the snow at sea level).
Skookum Drainage	Closed	Closed Jan 5th due to lack of snow (holiday storms rained away the snow at sea level).
Turnagain Pass	Open	Opened Dec 13th.
Twentymile	Closed	Closed Jan 5th due to lack of snow (holiday storms rained away the snow at sea level).
Seward District
Carter Lake	Open	Opened Dec 13th.
Lost Lake Trail	Open	Opened Dec 13th.
Primrose Trail	Open	Opened Dec 13th.
Resurrection Pass Trail	Closed	Closed to motorized use for the 2022/23 winter season per Forest Plan. Open next season.
Snug Harbor	Open	Opened Dec 13th.
South Fork Snow River Corridor	Open	Opened Dec 13th.
Summit Lake	Open	Opened Dec 13th.