Small Ski/Remote triggered slide at Coney’s

CB Avalanche Center2020-21 Observations

Date of Observation: 12/29/2020
Name: Dave Bumgarner

 

Zone: Southeast Mountains
Location: Coney’s Nose
Aspect: North East
Elevation: 10,800

 

Avalanches: Ski triggered/remote small D1 slide in the steeper section near the right of Coney’s nose. Was skiing the lower angle terrain and a small slide broke to my right and ran to the tree line.
No one was caught.
Slide slid on the early season snow 10–20 cm of large facets on the ground, broke around the shrubbery. (see photos)
Weather: Temp: Mid 20’s
Sky: Partly cloudy
Wind: light
Precip: S -1
Snowpack: Had a few collapses in undisturbed areas throughout our skin. Did not see any other avalanche activity beside our isolated slide. Multiple folks slaying Coney’s today skiing the main shots.

 

Photos:

Larger Than Expected Propagations

CB Avalanche Center2020-21 Observations

Date of Observation: 12/29/2020
Name: Drew Kelly

 

Zone: Southeast Mountains
Location: Red Coon Glades
Aspect: South East
Elevation: 11,100K

 

Avalanches: Lots of collapsing, and long shooting cracks. We climbed and “skied” terrain less than about 31 degrees. Nearing the 30 degree angle (+/- a degree or two) nearly everything collapsed and fractured. We sent continuous cracks nearly 200 ft across one slope, a distance that surprised us (see picture). There were numerous other slopes where cracks travelled 50+ft.

All moving snow seemed to break at the interface between the last few days’ storm slab and the older decomposing snow from previous weeks.
Weather: Occasional light breeze mostly near and above treeline, intermittent cloud cover, ~10-20F, light snow.
Snowpack: Snow depths varied between 1-2ft. In some places recent storm snow sat on bare ground; in other places that recent storm snow sat on a melt-freeze crust that was on top of faceting older snow.

 

Photos:

More persistent slabs

CB Avalanche Center2020-21 Observations

Date of Observation: 12/29/2020

 

Zone: Northwest Mountains
Location: Gunsight road
Aspect: North East
Elevation: 10,000

Avalanches: Intentionally triggered several road banks and small steeper rolls. All D1-1.5. Persistent slab problem was very reactive today. Poor vis limited obs in other areas.
Weather: Warmest in the morning with cold temps in the afternoon. Light snow and light winds throughout the day with maybe an additional inch or two of accumulation.
Snowpack: It’s broke. Multiple large booming collapses. Many shooting cracks. Surprisingly some steeper slopes around 35* cracked but did not slide. Snowpack was less reactive in areas that slide last week.

 

Photos:

Lower Snodgrass

CB Avalanche Center2020-21 Observations

Date of Observation: 12/28/2020
Name: Steve Banks

 

Zone: Southeast Mountains
Location: Lower Snodgrass
Aspect: North East
Elevation: 9800

 

Avalanches: None noted
Weather: Light snow throughout the day with even lighter winds. Mild temps felt like low 20’s. New snow accumulation of about 3-4” from overnight and through the day.
Snowpack: Weak AF. There is about a foot and a half of snow where we were. 4” below the surface is a thin buried weak layer (suspect SH/SF) which popped out in CT tests but did now propagate in ECTs. This will be another one to watch with this incoming storm or the next. Midway through the snowpack is the horribly weak weak layer. 2-4mm facets. This was resting on a 2” thick decomposing crust, with weak faceted snow (just becoming DH) on the ground. Multiple Easy to Moderate CT and ECTP test results on this weak layer, all above the crust.

 

The many shades of Yellow

CB Avalanche Center2020-21 Observations

Date of Observation: 12/27/2020
Name: Zach Kinler
Zone: Northwest Mountains
Location: Evans Basin

Aspect: East, South East, South

Elevation: 9300′-11,000′

Avalanches: No recent activity

Weather: Mostly sunny and pleasant on this afternoon tour. Winds were calm in sheltered areas. Highs remained below freezing.

Snowpack: The snowpack is still grumbling a bit, like a Stubborn old man sending back soup at the deli. There are a few steep slopes that have not avalanched and SOME of them produced collapses and cracking while others did not. The slopes that cracked did not run. Sensitivity has decreased however specific areas require thoughtful evaluation.

2-3″ new snow. Toured mainly on aspects from S through E. HS 60-70cm in sheltered terrain. Recent crusts from 12/22 and 12/26 have welded themselves into one thick crust 2-3 inches thick on steep south-facing slopes. Moving towards east, the crusts taper with faceting around the 12/22 MFcr. Small surface hoar capping facets was found at this interface once on due east.

 

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Splains Gulch

CB Avalanche Center2020-21 Observations

Date of Observation: 12/26/2020

Name: Jack Caprio

Zone: Kebler Pass Area

Location: Splains Gulch

Aspect: North East, East

Elevation: 9400′-10400′

 

Avalanches: Two small (D.5 and D1), older avalanches that failed on the 12/10 interface at some point over the last two weeks. The slides failed on small convexities on east-facing slopes below treeline.

Weather: Bluebird. Mild temps. Little to no wind.

Snowpack: We traveled mostly on E aspects below treeline. The snow depth ranged from 60-80 cm. Recently developed surface hoar is widespread below 10,000′, and spotty above that. While touring on a common skintrack, we did not notice any collapsing or whumphing. After venturing off the skin track a short distance, we still did not get any visual or audible signs of collapsing.

Staying skeptical about the persistent slab problem, we tried some stability tests which gave us propagating results. ECTP18. The column initiated on 3-4 mm faceted grains just below a 2 cm MF crust (12/10 interface). With our mild weather, signs of instability seem to be becoming less blatant, however, our persistent slab structure on N-E facing terrain continues to linger around.

Photos:

 

Still Sketchy

CB Avalanche Center2020-21 Observations

Date of Observation: 12/24/2020
Name: Joey Carpenter

 

Zone: Northwest Mountains
Location: LJ
Aspect: South, South West, West, North West
Elevation: 9.4-10.6

 

Avalanches: Repeater path on purple ridge, Natural (photo from SL)

Saw another large D2 sized natural on the E facing ridge near Angel Pass. We were very far away, no photo.
Weather: Clear and cold in the morning. Temps were around zero at the TH at 900 and made it into the mid twenties by 2p. Wind was calm overall in areas we traveled but large plumes from Northerly winds were transporting large amounts of snow above the S Baldy bowl for much of the morning. NTL and ATL terrain that has any western tilt has been ravaged by the wind event on 12/22. Even relatively sheltered terrain in the Western compass has seen significant impact from wind in this area.
Snowpack: Cracking and collapsing are the world we live in. The snowpack is very weak, encouraging us to be exceptionally careful. The difference today, from the past two weeks, is the feedback is less predictable, less consistent, and larger. Collapses that would’ve propagated short distances two weeks ago are now impacting much larger swaths of the snowpack as slabs stiffen. The most notable of the 30+ collapses we got today was on a lap track that we’d traveled on earlier in the day. We got 3 large collapses with accompanying cracks on slopes approaching 30 degrees in an area that had already been impacted by skier weight twice.

 

New natural

CB Avalanche Center2020-21 Observations

Date of Observation: 12/24/2020
Name: Sam L

 

Zone: Northwest Mountains
Location: Purple ridge
Aspect: North, North East
Elevation:

 

Avalanches: New natural observed on purple ridge.
Weather: Calm, clear and cold
Snowpack: Observed new natural on purple ridge from across the valley. It appeared to entrain only drifted storm snow and did not step down. This same path ran on or around 12/13. Crown and flanks looked to be softened, maybe it ran yesterday or the night before but was in the clouds until this morning?

 

Photos: