Sluffs on Gibson Ridge

CB Avalanche CenterCBAC Observations

Date of Observation: 02/18/2022
Name: Zach Guy

Zone: Southeast Mountains
Route Description: E/NE aspect of Gibson Ridge. Viewed from Highway 135.

Observed avalanche activity: Yes
Avalanches: A few long running sluffs, D1 or maybe 1.5 in size, that appear to be recently skier or snowboarder triggered.
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A bit less new snow than expected on Purple Ridge

CBACCBAC Observations

Date of Observation: 02/17/2022
Name: Eric Murrow

Zone: Northwest Mountains
Route Description: Up standard Purple Ridge track and descended from the ridge through Purple Palace.

Observed avalanche activity: Yes
Avalanches: Observed numerous small Loose Dry avalanches on north through east aspects coming out of rocky upper elevation terrain. One fresh shallow slab immediately below a ridge top in Wolverine Basin and another deeper-looking crown on an northeasterly-facing part of the apron in Wolverine.
Weather: Partly cloudy skies in mid-morning, orographically driven cloud cover and very light snowfall midday over the spine of the Ruby Range, and clearing skies by sunset. Moderate northerly winds with stronger gusts through 1pm shifting to the northwest later in afternoon.
Snowpack: New snow accumulations maxed out at 5 inches on Purple Ridge near treeline. North to northwest winds transported snow throughout the day in the Ruby Range onto east through south aspects at upper elevations. At ridgetop, I was able to get some ski-length cracking in fresh cornice formation, but drifted features up to 14 inches deep did not crack. On shaded slopes below treeline, I found the 5 inches of storm snow resting on a mix of weak facets, friable melt/freeze crusts, and supportive windboard and did not find signs of instability. It seems like there were isolated Wind Slabs up high, the potential for old hard slabs from previous winds, and sluffs on weak shady slopes, but no Storm Slab problem.

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Large natural avalanche on East Beckwith

CBACCBAC Observations

Date of Observation: 02/17/2022
Name: Eric Murrow

Zone: Northwest Mountains
Route Description: Observation from East Beckwith via social media message

Observed avalanche activity: Yes
Avalanches: Large natural avalanche on a northeast aspect. Appears to be a slab, but can’t make out the exact details. Certainly large enough to bury and kill a person.
Weather:
Snowpack:

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Fluff, slough, frozen tracks & crust…

CB Avalanche CenterCBAC Observations

Date of Observation: 02/17/2022

Zone: Southeast Mountains
Route Description: A few laps at Coney’s. 9,600-10,800 ENE aspects. Started on the standard skin track, but traversed north into the open terrain; climbed the ridge just south of the main bowl.

Observed avalanche activity: Yes
Avalanches: Soft sloughs (small) on everything over 35 degrees.
Weather: Clear skies. 10 degrees at 9AM warming into the 20s by the end of the tour. Light N wind at the ridge.
Snowpack: 5-8cm of new snow on a firm crust. In the steepest terrain (at the top and near the bottom), new snow was sloughing easily. If the terrain were steeper I could imagine the sloughs moving fast and far.

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Powder on the sand box

CBACCBAC Observations

Date of Observation: 02/16/2022
Name: Eric Murrow & Evan Ross

Zone: Northwest Mountains
Route Description: Schuylkill. NE-E-S, 9,000-11,300ft.

Observed avalanche activity: Yes
Avalanches: More skier triggered sluffs. The most notable was initiated on the first turn off the ridge and ran 1,000ft and through a good section of 35-degree terrain in the avalanche track. That part wasn’t necessarily new. However, the additional new snow added enough volume to push this sluff to the line of a D2 avalanche. NE facing slope.  Low in the track, the moving loose avalanche released a small, thin hard slab where previous winds drifted snow.

Weather: Mostly cloudy with convective bursts of snow moving through like a summertime thunderstorm. During the clearings, the snow was clearly blowing off of Scarps Ridge and periods of moderate winds where drifting snow at lower NTL elevations.

Snowpack: 4″ of new snow was measured at 4pm, 9,700ft. We didn’t encounter any changes to the current list of avalanches problems. Mostly just added volume for the loose snow avalanche problem and drifting snow at upper elevations.

The old snow surface in many areas is extremely weak. Similar to early season conditions when we have a large-grained faceted snowpack that is just starting to accumulate new snow. The only difference is that it’s February and the weak layer is widespread. Northerly facing slopes are a sandbox of NSF. Easterly facing slopes and some NE facing slopes had a thin collapsible crust capping those same large-grained and very weak NSF. Some of those crusts looked like they could collapse with little load and aid in propagation. Any triggered avalanche, slab or loose, would then gouge into the weak old snow, gaining additional volume.

South and SE-facing slopes in this area had strong crusts with many peculation columns extending into the snowpack below. Here we couldn’t initiate sluffs in the new snow on 38-degree slopes.

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Check on the P-Divide Avalanche

CBACCBAC Observations

Date of Observation: 02/15/2022
Name: Evan Ross

Zone: Northwest Mountains
Route Description: Slate River to Paradise Divide.

Observed avalanche activity: Yes
Avalanches: Headed up to the previously reported avalanche on Paradise Divide for a little check-in since it didn’t quite fit the mold. This avalanche failed on a thin crust capping 1mm, very soft, faceted grains over harder 1F hard faceted grains. The slab above was P+ hard. As reported, the crown was in fairly low angle southerly facing terrain.

After closer inspection, this appeared to be a monster wind wale that failed on a weaker than average south-facing snowpack due to the lower angle of the terrain. The fetch for this avalanche is massive, square mile range. The fetch from the paradise divide area has created a number of hard slabs that have loaded into the SE to SW facing slopes below the pass.

In a location near the crown, on a steeper 35 degree south-facing slope, without the recent wind loading. The surface crust was 3 to 4cm’s thick, with large percolation column extending into the facets. The snowpack here was only about 100cm’s deep and didn’t have much layering given the lack of storms this winter.

I didn’t encounter any obvious signs of instability while traveling on the margins of some of the other hard slabs in the area. Once you were out on the slabs there was no way the weight of a human was going into the snowpack given how hard the snow now is. However if you did manage to find a trigger point you could get a similar result to this avalanche. The snowpack has most likely become quieter since the last party had come through this area.

Weather: Mostly cloudy, with a nice break in the clouds early afternoon for things to both warm and soften up. Overcast by late afternoon. Warm and breezy.

Snowpack: Snow surface obs between 11,500ft and 10,500ft. Westerly slopes were made up of large-grained facets in some areas, and a 2cm crust capped the facets in other areas. A slight change in slope angle or aspect allowed for the crust vs straight facets. SW and SE aspects had a slightly stronger crust but still very concerning with a load. On south facing slopes, the crust was in the 3 to 4 cm range with big percolation column going down into the facets. Not much layering in this snowpack given the few storms this winter and dry 2022…

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Collapse

CBACCBAC Observations

Date of Observation: 02/14/2022
Name: Zach Guy

Zone: Southeast Mountains
Route Description: The center of the donut hole

Observed avalanche activity: No
Snowpack: Got a collapse on a recently drifted feature in tight trees on a NE aspect near treeline. The slab was about a foot thick, and about the size of a dinner table. The slab formed in trees because there was an open northerly fetch upwind that funneled into the trees at this location.

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As expected

CB Avalanche CenterCBAC Observations

Date of Observation: 02/13/2022
Name: Rob Strickland

Zone: Southeast Mountains
Route Description: Loop

Observed avalanche activity: Yes
Avalanches: NTL: Manageable sluffs in E/NE terrain. Some crusts as you dip south. Soft as you dip north.
ATL: wind blown
Weather: Sunny
Snowpack: The wind blew away the surface hoar

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Mt Emmons

CBACCBAC Observations

Date of Observation: 02/13/2022
Name: Evan Ross

Zone: Southeast Mountains
Route Description: 9,000ft-11,500ft. NW-N-E

Observed avalanche activity: No

Avalanches: Small loose dry avalanches on steep slopes near 40 degrees. Mostly northerly facing, and 1 east facing slope around 11,400ft.

Weather: Clear, warm, calm.

Snowpack: Small sluffs were the main thing we ran into on steep slopes, near 40 degrees. We didn’t encounter a persistent slab avalanche problem on the ridge between Wolverine and Redwell basin up to 11,500ft in elevation. Where we skied off the east side of the ridge just below 11,500 we triggered small sluffs. There could have been a couple isolated pockets with a slab avalanche problem in that area that were slightly higher up. Didn’t see much for loading in the alpine.

Photos:

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