Mon, January 10, 2022 Turnagain Pass Avalanche Forecast

Mon, January 10th, 2022

Alpine
Above 2,500'

Considerable (3)

Treeline
1,000'-2,500'

Considerable (3)

Below Treeline
Below 1,000'

Considerable (3)

Alpine Above 2,500'		Considerable (3)
Treeline 1,000'-2,500'		Considerable (3)
Below Treeline Below 1,000'		Considerable (3)

Danger Scale:

No Rating (0)

Low (1)

Moderate (2)

Considerable (3)

High (4)

Extreme (5)

Avalanche Problem 1

Storm Slabs
Almost Certain

Very Likely

Likely

Possible

Unlikely

Likelihood
Historic

Very Large

Large

Small

Size

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.

Likelihood of Avalanches

Terms such as "unlikely", "likely", and "certain" are used to define the scale, with the chance of triggering or observing avalanches increasing as we move up the scale. For our purposes, "Unlikely" means that few avalanches could be triggered in avalanche terrain and natural avalanches are not expected. "Certain" means that humans will be able to trigger avalanches on many slopes, and natural avalanches are expected.

Size of Avalanches

Avalanche size is defined by the largest potential avalanche, or expected range of sizes related to the problem in question. Assigned size is a qualitative estimate based on the destructive classification system and requires specialists to estimate the harm avalanches may cause to hypothetical objects located in the avalanche track (AAA 2016, CAA 2014). Under this schema, "Small" avalanches are not large enough to bury humans and are relatively harmless unless they carry people over cliffs or through trees or rocks. Moving up the scale, avalanches become "Large" enough to bury, injure, or kill people. "Very Large" avalanches may bury or destroy vehicles or houses, and "Historic" avalanches are massive events capable of altering the landscape.

Signal Word	Size (D scale)	Simple Descriptor
Small	1	Unlikely to bury a person
Large	2	Can bury a person
Very Large	3	Can destroy a house
Historic	4 & 5	Can destroy part or all of a village

More info at Avalanche.org

The avalanche danger is rising as snow continues to fall across the advisory area. As of 5:00 this morning, weather stations are showing 7-9″ of new snow, and another 3-5″ is expected during the day. Strong easterly winds have been blowing 25-50 mph since yesterday evening, and the Sunburst weather station is recording gusts just under 80 mph. This weather system is hard at work loading snow on top of a variety of weak surfaces including surface hoar, near-surface facets, and the New Year’s crust. In addition to the strong winds and heavy snowfall, we are also seeing the temperatures rising into the low 30’s this morning. Those rising temperatures mean heavier wet snow is stacking up on top of cold, dry snow, creating an upside-down storm layer that will be very touchy. This is a dangerous setup, and it is likely a person will be able to trigger an avalanche 2′ deep or deeper by the middle of the day today. If this storm ends up producing more than is expected as of this morning, we will be flirting with HIGH DANGER by the end of the day. Pay attention to signs of increasing danger, especially for fresh avalanche activity as the storm continues.

While the biggest avalanches will be found on wind-loaded slopes, we are also expecting to see dangerous avalanche conditions in frequently traveled sheltered terrain (think about the steeper rollovers in the Tincan trees). If you plan on getting out today, conservative decision making will be key. It is likely avalanches may be triggered remotely from above, below, or adjacent to steep terrain. The New Year’s crust will make for a very smooth bed surface, which means avalanches are likely to run fast and far. Be mindful of the terrain above you, and be sure to avoid spending any time in runout zones below steeper slopes. This is the kind of day to play around in the flats and stay on very mellow slopes. Everyone is thrilled to finally get a good refresh, but the current setup is nothing to mess with.

Loose Snow Avalanches: Rain lines are expected to rise up to 1500′ this morning, which will most likely lead to wet loose avalanches on steep slopes in lower elevations. At higher, colder elevations, we can expect to see dry loose avalanches running fast on top of the New Year’s crust. These will have enough volume to carry a person, and can have severe consequences in terrain traps like trees, rocks, alders, and open creeks.

New snow is getting loaded on a variety of weak surfaces, including near-surface facets, buried surface hoar, and a nasty crust. Large avalanches are likely as the snow continues to stack up. Snow surface at 1800′ on Center Ridge, 01.09.2022.

I described the current setup in this video from the field yesterday:

Weather

Mon, January 10th, 2022

Yesterday: Temperatures slowly climbed out of the single digits F during the day yesterday through last night, and are currently in the upper 20’s to low 30’s F. Light snowfall started picking up in the afternoon, with weather stations showing 7-9″ snow this morning. Easterly winds were blowing 5-10 mph for most of the day, with stronger winds picking up to 25-50 mph starting yesterday evening.

Today: Heavy snowfall is expected to taper off mid day, with another 3-5″ expected at Turnagain Pass and Girdwood, up to 10″ in Portage and Placer, and 1-3″ in Summit Lake. Strong easterly winds are blowing at 25-55 mph with gusts to 78 mph this morining, and are expected to slowly drop to 20-25 mph with gusts at 45-50 mph by late afternoon. The rain level is expected to rise up to around 1500′ this morning before dropping back down to 500-800′ later in the day. Temperatures are expected to stay in the upper 20’s to low 30’s F all day.

Tomorrow: The weather is expected to calm down tomorrow, with light snowfall bringing another 2-3″ overnight and a trace during the day tomorrow. Low temperatures will be in the mid to upper 20’s tonight, and will stay in the mid 20’s during the day tomorrow. Light easterly winds will stay around 5-10 mph under mostly cloudy skies.

PRECIPITATION 24-hour data (6am – 6am)

	Temp Avg (F)	Snow (in)	Water (in)	Snow Depth (in)
Center Ridge (1880′)	19	8	0.7	72
Summit Lake (1400′)	9	2	0.1	24
Alyeska Mid (1700′)	17	9	0.7	46

RIDGETOP 24-hour data (6am – 6am)

	Temp Avg (F)	Wind Dir	Wind Avg (mph)	Wind Gust (mph)
Sunburst (3812′)	18	NE	21	78
Seattle Ridge (2400′)	18	SE	6	29

Observations

Recent Observations for Turnagain Pass

Date	Region	Location	Observer
05/28/22	Turnagain	Avalanche: Turnagain Pass – late May wet slab cycle	CNFAIC Staff
05/21/22	Turnagain	Avalanche: Magnum, Lipps and Tincan	CNFAIC Staff
05/17/22	Turnagain	Avalanche: Sunburst	CNFAIC Staff
05/17/22	Turnagain	Observation: Tincan Ridge	Joe Kurtak
05/11/22	Turnagain	Avalanche: Cornbiscuit and Magnum west faces	CNFAIC Staff Forecaster
05/07/22	Turnagain	Observation: Granddaddy	Kit Barton
04/29/22	Turnagain	Observation: Sunburst wx station	AS/ MM/ AM/ NH
04/28/22	Turnagain	Observation: More Turnagain Pass/Summit Lake wet slab activity	Alex Marienthal
04/27/22	Turnagain	Observation: Magnum	Sykes / Buttrick Forecaster
04/27/22	Turnagain	Observation: Girdwood/Summit/Turnagain Road obs	A S

Riding Areas

Updated Wed, June 01st, 2022

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 as of May 1 per Forest Plan.
Placer River	Closed	Closed as of April 25th due to insufficient snow coverage.
Skookum Drainage	Closed	Closed as of April 1st per Forest Plan.
Turnagain Pass	Closed	Closed as of June 1st.
Twentymile	Closed	Closed as of April 6th due to insufficient snow coverage.
Seward District
Carter Lake	Closed	Closed as of May 1 per Forest Plan.
Lost Lake Trail	Closed	Closed as of May 1 per Forest Plan.
Primrose Trail	Closed	Closed as of May 1 per Forest Plan.
Resurrection Pass Trail	Closed	Closed as of May 1 per Forest Plan.
Snug Harbor	Closed	Closed as of May 1 per Forest Plan.
South Fork Snow River Corridor	Closed	Closed as of May 1 per Forest Plan.
Summit Lake	Closed	Closed as of May 1 per Forest Plan.