Sun, March 31, 2013 Turnagain Pass Avalanche Forecast

Sun, March 31st, 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

Wind slabs formed during Friday, 3/29’s 8-10” of snow were still releasing yesterday. These were in the foot deep category and on all aspects above treeline. A few observed were: one natural that occurred on the east face of Seattle Ridge and one on the southerly tip of Tincan Proper. Check the obs page for a few more details from other observers. The sun and warm temperatures likely played a role in increasing the instability of the slabs.

Today I’m expecting these to be harder to trigger but still the primary concern due to their slab nature. The snowpack is quite variable currently with wind slabs sitting on crusts on south, east and westerly aspects (some of which have facets surrounding them) and on old wind crust/slabs on northerly aspects. Quick hand pits looking for easy shears between snow layers in the top 12-18” of the pack is one good tool to suss out any slab that has yet to heal.

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

Wet point release and damp point release avalanches should be expected today on south, east and westerly facing slopes approaching 40 degrees and steeper. Watch for rollerballing in the surface snow and be suspect of areas and aspects where the snow surface is warm and gloppy.

Additional Concerns:
Cornices. Warm temperature are known for contributing to the failure of cornices. A good thing to keep in mind when planning your route.

Surface Conditions:
Yesterday’s warmup affected the south, west and easterly aspects as well as below treeline locations. These areas that became damp or wet yesterday are likely undergoing a superficial refreeze now but should moisten through the day. Upper northerly aspects sport variable wind affected, but dry, snow.

Weather

Sun, March 31st, 2013

It was a WARM day yesterday with temperatures reaching the 40deg mark at sea level and 30F at 3,000′. Skies were partly cloudy with a few flurries (drizzle below 1500′) late in the day. Winds were light from the east (5mph gusting 15mph). The last measurable snowfall was 8-10 € on Friday 3/29.

This morning we are looking at mostly cloudy skies, fog and temperatures around freezing (32F) at 1,000′ and ~20F on the ridgelines. Temperatures should rise to the upper 30’s at 1000′ and upper 20’s at 3,500′. A chance for an inch of snow is on the radar (drizzle below 1000′) as instability showers are over the region. Winds are from the east currently, 10mph gusting ~15mph, and should remain today. I’m hoping the cloud cover will burn off a bit for the CORN HARVEST so cross your fingers.

Monday, and through the early part of this week, it looks as though a high pressure ridge will build over western Alaska. This should bring us light northerly wind and mostly clear skies.

Fitz will issue the next advisory tomorrow morning, April 1st.

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.