Tue, January 08, 2019 Turnagain Pass Avalanche Forecast

Tue, January 8th, 2019

Alpine
Above 2,500'

Low (1)

Treeline
1,000'-2,500'

Low (1)

Below Treeline
Below 1,000'

Low (1)

Alpine Above 2,500'		Low (1)
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

Normal Caution

Normal Caution

Normal Caution means triggering an avalanche is unlikely but not impossible.

More info at Avalanche.org

It has been a week since we had any report of human triggered avalanche activity and observers are not reporting signs of instability. As a mostly calm and cold weather pattern dominates our area and continues until the weekend, we are in the “normal caution” phase of avalanche concerns. These include:

Triggering an outlier avalanche. This would most likely be an ‘unsupported slab’ that sits above a cliff or steep rocky terrain. There may still be a pocket of buried surface hoar lurking.
Triggering a cornice fall. Remember they break farther back from ridges than often expected. Give them a wide berth.
Sluffs on steep slopes. These have been mostly small so far but as the surface becomes weaker the potential will increase.

Being in the wrong place at the wrong time and getting caught in a glide avalanche also remains a concern. Glide cracks are opening and releasing and have been observed throughout the advisory area in both the Alpine and Treeline elevation bands. It is important to minimize time spent underneath the glide cracks. Release is unpredictable and not human triggered. Be on the lookout for cracks and wrinkled looking snow (often a precursor to cracking).

Remember LOW hazard doesn’t mean NO hazard! It is still important to look for signs of instability and use good travel techniques.

Recent glide avalanches and glide cracks opening in Lynx Creek drainage, 1-7-19.

Lipps glide cracks, 1-7-19.

Additional Concern

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

South of Turnagain – Lynx Creek/Johnson Pass/Summit Lake zone: A poor snowpack structure exists in these areas. The buried surface hoar that we have been talking about over the past week has been found as well as facet/crust combinations in the bottom of the snowpack. The New Year’s storm overloaded a variety of these weak layers as can be seen in photos from the avalanche activity throughout Summit Lake. If you’re headed this way, the snowpack becomes more complex – evaluate terrain exposure and the snowpack as you travel.

The facet/crust combination continues to be a layer of concern in Summit Lake. Observers over the weekend found this set-up to be stubborn to initiate but still consistently reactive in multiple stability tests.

Weather

Tue, January 8th, 2019

Yesterday: Skies were clear, winds were light and temperatures were cold. Upper elevation highs were in the single digits to low teens and valley bottom lows were in the negative teens with the inversion. Valley fog conditions persisted. Clouds built in the late afternoon and temperatures increased a little overnight.

Today: Is forecast to be partly to mostly cloudy with a chance of snow showers and light southeast winds. Temperatures will be in the teens and low 20Fs. Skies clear again overnight.

Tomorrow: Sunshine and cooling temperatures return Wednesday and will be the dominant weather through Friday. Stay tuned for a change over the weekend with a potential return, according to the National Weather Service to “warmer, wetter, and overall more unsettled weather as we head into next week”.

*Seattle Ridge weather station was heavily rimed and the anemometer (wind sensor) was destroyed. We are currently working to replace it.

PRECIPITAT

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

	Temp Avg (F)	Snow (in)	Water (in)	Snow Depth (in)
Center Ridge (1880′)	8	0	0	55
Summit Lake (1400′)	-3	0	0	21
Alyeska Mid (1700′)	5	0	0	45

RIDGETOP 24-hour data (6am – 6am)

	Temp Avg (F)	Wind Dir	Wind Avg (mph)	Wind Gust (mph)
Sunburst (3812′)	10	SW	3	16
Seattle Ridge (2400′)	11	*N/A	*N/A	*N/A

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.