Still crackin out in Cement

CBACCBAC Observations

Date of Observation: 03/13/2022
Name: Zach Guy

Zone: Southeast Mountains
Route Description: Snowmobiled on various aspects to the headwaters of Cement Creek, up to 12,000 ft.

Observed avalanche activity: Yes
Avalanches: More small wet loose activity today at all elevations, southern half of the compass. A few fresh cornice falls on Double Top to D1.5. A handful of small to large wind slabs that probably ran Friday above treeline. One deeper and fresher looking slab avalanche on a SE facing slope above treeline on Gothic Peak that ran sometime in the past few days.
Weather: Warm and sunny most of the day. Clouds quickly increased to overcast from 3 to 4 p.m. Moderate ridgetop winds this afternoon were starting to drift snow.
Snowpack: Still getting fairly consistent shooting cracks and remotely triggered mini slabs in creek beds below treeline on untrammeled shady aspects. Signs of instability diminished as I got higher in elevation, although I did get easy propagating results under a 2 foot slab on the Double Top Ridgeline (NE aspect, 11,600′). These instabilities are all on the sandbox layer, 18″ to 24″ deep, on average fist to fist+ hard and 2mm in size. Tried snowmobile cutting several hard wind slabs above treeline on small, supported features and the only result was me getting bucked off the sled.

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Irwin mitigation

CBACCBAC Observations

Date of Observation: 03/12/2022
Name: Irwin Guides

Zone: Northwest Mountains
Route Description: Irwin Tenure: Upper Upper West Wall

Observed avalanche activity: Yes
Avalanches: These were largely unreactive to ski cuts but reactive to AE, most failing on the suncrust beneath this last storm cycle.
Field of Screams HS-AE-R1-D1.5-O FC (30cm x 30m x 200m)
Castle Valley Left HS-AB-R1-D1-O FC (70cm x 10m x 100m)
Castle Valley Right HS-ASc-R1-D1-O FC (20cm x 10m x 220m) ski cut at the top.

Photos:

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A couple of very large naturals in the alpine. One ran today.

CBACCBAC Observations

Date of Observation: 03/12/2022
Name: Zach Guy

Zone: Northwest Mountains
Route Description: Upper Slate, traveled on easterly facing terrain to 11,600 ft.

Observed avalanche activity: Yes
Avalanches: One very large (D3) persistent slab ran off of the east face of Peeler Peak today. Another large persistent slab ran below Scarp Ridge sometime last night or yesterday afternoon.
Spotted a handful of wind slabs that ran yesterday at higher elevations, D1 to D2, on SW to SE aspects.
A handful of small wet loose avalanches ran today near and below treeline. Observed slides on east to south aspects, sun was moving towards westerlies as my field day ended.
Weather: Mild temps, few clouds, light breeze with no transport observed all day.
Snowpack: Northwest winds affected the snow surface at all elevations here, with lots of soft sastrugi and obvious lobes of drifted slabs at all elevations. I was able to produce shooting cracks on some below treeline drifts where the slabs were thinner and softer. Near ridgetop, the slabs were meaty and dense and more stubborn. The persistent slab is about 3 to 4 feet thick here and evolving into a hard slab. Although we did not get any signs of instability on skis all day, we got one collapse while digging out a stuck sled. A quick test on a NE aspect at 11,000 ft produced propagating results on the dry spell layer after modifying the ECT into a “deep tap ECT”. No results under normal loading steps (ECTX). The layer is 4F- hard, 1mm in size under a 115 cm slab up to 1F hard.

Photos:

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More natural avalanches on the east side

CBACCBAC Observations

Date of Observation: 03/11/2022
Name: Eric Murrow

Zone: Southeast Mountains
Route Description: Pavement observations from HWY 135 and Taylor Canyon.

Observed avalanche activity: Yes
Avalanches: Although skies were fairly clear, the thin cloud cover made distancing viewing a challenge. A couple of fresh-looking debris piles above Copper Creek and near WSC Peak on east and southeast aspects (vis was too poor to code with any confidence). Two natural avalanches on shady slopes below treeline in Taylor Canyon (D1’s , these looked older with a bit of refill so maybe from 2/23-2/25 avalanche cycle). One of the East Chutes on Park Cone had a reasonably fresh crown that propagated across most of its start zone (Park Cone is outside the CBAC forecast area but is similar to the shallower snowpack in the Southeast Mountains forecast area).
Weather: Partly cloudy skies with blowing snow were observed at upper elevations. East through south aspects appeared to receive the brunt of wind-loading.
Snowpack:

Photos:

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Natural activity on Axtell, Emmons, and Scarp Ridge

CBACCBAC Observations

Date of Observation: 03/11/2022
Name: Zach Guy

Zone: Northwest Mountains
Route Description: As viewed from Gothic Peak

Observed avalanche activity: Yes
Avalanches: A handful of D1 to D2 slab avalanches in wind drifted terrain that failed recently. Most looked like wind slabs failing within the storm snow. One appeared to be a large persistent slab below Scarp Ridge. See photos.

Photos:

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Not your ordinary wind slabs

CBACCBAC Observations

Date of Observation: 03/11/2022
Name: Zach Guy

Zone: Southeast Mountains
Route Description: Traveled on southerly aspects of Gothic Peak up to about 11,400 ft. Conditions worse than expected, bailed on our route plan and skied on NW, W, and SW aspects of Snodgrass instead.

Observed avalanche activity: Yes
Avalanches: On wind loaded southerly aspects, we found sensitive wind slabs that we could easily trigger remotely failing on the 3/8 crust. Even from locations without any drifting or slab formation, shooting cracks would connect to a drifted feature and release it. We remotely triggered about 5 small wind slabs on drifted rollovers below treeline on S or SE aspects. Near treeline, we remotely triggered a large wind slab in the “mini spoon” that propagated 400 vertical feet above our location and crossed the whole slope; crown was 10″ to 24″+ thick. There was also a large natural that came out of the Spoon yesterday or last night, crown filled in.
With decent visibility, we spotted a handful of D1 to D2 slab avalanches that failed recently, recorded in a separate ob. Most looked like wind slabs failing within the storm snow. One appeared to be a large persistent slab below Scarp Ridge.
Weather: Cold and windy. Large plumes of blowing snow off of the high peaks. Continuous drifting in valley floor. Mostly clear skies overhead, some hazy clouds lingering over the Ruby Range.
Snowpack: About 5″ of settled storm snow over the 3/8 crust on southerly aspects. This crust formed during the one day of sunny weather in the middle of last week’s storm cycle, and I suspect there is some radiation recrystallization associated with it, given its behavior.
On NW aspects below treeline on Snodgrass, we got numerous collapses on the sandbox layer about 2 feet down. Some collapses required stomping, some went while breaking trail. We were in tight trees and collapses didn’t radiate very far. In windsheltered southwest facing terrain, we found stable conditions.

Photos:

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It’s still snowing

CBACCBAC Observations

Date of Observation: 03/10/2022
Name: Eric Murrow

Zone: Northwest Mountains
Route Description: Washington Gulch

Observed avalanche activity: Yes
Avalanches: Visibility was poor so I did not observe a crown, but I spotted one fresh debris pile in a southwest gully on Gothic Mtn, D1.5.
Weather: From noon to 4 pm, skies were mostly cloudy with light snowfall. Winds were light with moderate gusts up to 11,400 feet.
Snowpack: I was snowmobiling for fun, but dug a quick profile on a northeast-facing slope at 11,450 feet – see photo. I found two interfaces, around 1 and 2 feet down, that produced easy, small-column test results but only produced tiny cracks on small test features while snowmobiling. The mid-February facet “drought layer” was down about 115cm below a stiff, cohesive slab. The weak layer from mid-February has improved a small amount in this area, but the stark difference in grain size and hardness with the overlying slab remains obvious in the profile wall.

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A few collapses

CBACCBAC Observations

Date of Observation: 03/10/2022
Name: Zach Guy

Zone: Northwest Mountains
Route Description: Lower Slate and Lower OBJ, various aspects traveling mostly below treeline.

Observed avalanche activity: No
Avalanches: Had so-so vis into Redwell Basin and didn’t see anything notable. Maybe a couple of thin, small soft slabs on northerly below treeline.
Weather: Wintery temps. Very light snowfall this afternoon. Light northwest winds were drifting snow near valley bottom. No transport higher up.
Snowpack: About 6″ to 8″ new. Got a couple of large, rumbling collapses near the valley bottom on moderate angled NE aspects. Got one deep but localized collapse on a flat ridgeline at 11,000ft. These were all on the sandbox layer about 3 feet down. Got a few minor cracks and one shallow collapse that radiated about 40 ft on a steep south facing slope. This was on the 3/8 crust, which is a thin, soft crust that developed during the one sunny day between storms this week. There was about 6″ of storm snow above the crust; not sure there’s enough to produce a slab avalanche unless you were in a drifted location. We traveled on steep southeast aspects and a few east/northeast facing bed surfaces from the 2/23 cycle with no signs of instability on either.

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Couple Small Wind Slabs

CBACCBAC Observations

Date of Observation: 03/10/2022
Name: Evan Ross

Zone: Southeast Mountains
Route Description: The old reliable, park at the bottom and look up at the mountain tour.

Observed avalanche activity: Yes
Avalanches: A couple of small wind slabs on Whetstone. These were D1 to D1.5 in size. The only appeared to involve storm snow and didn’t propagate very wide. Probably ran yesterday during the stronger winds. ATL E to NE. Nothing else was observed while looking into those mountains.

Photos:

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Stompin around Elk Creek

CBACCBAC Observations

Date of Observation: 03/10/2022
Name: Zach Kinler

Zone: Northwest Mountains
Route Description: Kebler Pass trailhead to Elk Creek, toured up ridge above the creek. 9,000 ft-10,500 ft

Observed avalanche activity: No
Avalanches: No new avalanches observed on this tour. Very limited views into the surrounding upper elevation terrain.
Weather: Broken skies and higher clouds gave way to low clouds, moderate snow and some wind around 2:30 as a squall moved in. Temps remained quite chilly, felt more like January than March.
Snowpack: Walked around and jumped on a number of below tree line, northeasterly start zones, most of which avalanched early in the late February cycle. Generally, a soft 60-70 cm slab is resting on the bed surfaces in this zone. Bed surfaces themselves were a variably thick 1 finger hard crust capping 4 finger, 2 mm facets which do appear to be gaining strength. Very few signs of instability were observed underfoot or in a test pit other than 1 small leeward feature which had around 2ft of drifted snow and produced some small cracks in the new snow. No collapses or cracking were observed on the deeper weak layers on either slopes that avalanched or in-tact slopes.

 

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