Stay Snoddy

CB Avalanche Center 2020-21 Observations

Date of Observation: 01/09/2021
Name: Chris Martin

 

Zone: Southeast Mountains
Location: Snodgrass/Gothic Road
Aspect: North, North East, East
Elevation: 9000′-10000′

 

Avalanches: Continue to hear localized whumps in undisturbed snow where slabs remain stiff.
Weather: Partly Cloudy, warm, Sunny, no winds, Cold end to the day below Gothic road around the northern captures of the compass.
Snowpack: Toured from East onto the N-NE portion of the compass, BTL. Observed slabs decomposing into softer snow. Where we dug, we still observe a F-1F slab structure, that 1F portion has shrunk with time, slowly becoming softer from the top down. From last weekend to now, we are no longer seeing propagating test results in this location. Where slabs remain stiff in isolated terrain, localized whumpfs continue to be experienced.

HS 80cm Snodgrass 9800′

48 cm 1F-F Slab that is deteriorating
-over- (DEC 10th PWL 2-3mm FC)
32cm FC/DH 2-3mm

No propagating test results on DEC 10th Layer
CTMSC 48cm down (Dec 10th PWL)

 

Mt Axtell

CBAC 2020-21 Observations

Date of Observation: 01/09/2021
Name: Jared Berman & Jack Caprio

Zone: Northwest Mountains
Location: From Splains Gulch ascended the West face to the summit of Axtell. Skied South facing bowl before traveling back up S/SW ridge where we then skied the West face of Axtell back down to sleds
Aspect: North East, East, South-West, West
Elevation: 10,100ft – 12,500ft

Avalanches: None observed.

Weather: Broken clouds throughout the day and light winds from the NE. Several short periods of very light snowfall accumulating only trace amounts near and above treeline.

Snowpack:

The snowpack is still showing clear signs of instability on many aspects. However, collapsing and shooting cracks are only happening on specific terrain features and have started to become more stubborn.  Slabs are slowly faceting away but there are still many areas that hold a dangerous persistent slab structure.

While ascending a westerly aspect below treeline, we felt periodic collapsing in open meadows where we found soft slabs resting on top of depth hoar (12/10 interface). These collapses were almost always initiated by the third skier. HS on west aspects is shallow near and below treeline averaging about 75cm.

Near treeline on a SW aspect produced collapsing as well. One snowpit at this elevation/ aspect showed a 4F slab resting on top of Fist hard weak faceted snow. An Extended Column Test produced at ECTN21 at this location.

Moving around the compass to NE aspects we continued to experience several occasions of collapsing near and above treeline. Recent northerly winds did a number on start zones of the NE facing bowls of Axtell. These winds have created thin snow cover just below ridgetops that will surely weaken and become a problem at our next significant loading event.

We spent little time on east aspects, but experienced the most exciting results in these areas. A large collapse was observed with shooting cracks that ran about 30ft on a small East facing convexity at 10,000′. A snowpit dug adjacent to the collapse yielded our only propagating results of the day (ECTP 14). These failures were initiated on a thin MF crust sitting on top of the depth hoar (12/10 interface).

Continuing to a Southerly aspect, the skiing was surprisingly great with the exception of areas with a stiff sun crust on steeper slopes. Lower angled sunny slopes continued to ski great.

Bottomline: Many suspect slopes are weakening as slabs are faceting out. Obvious signs of instability are becoming rarer although they are still present.  W-N-E facing slopes below treeline slopes continue to maintain a persistent slab structure, while East seems to be the most concerning.

 

Photos:

Faceting Slabs

CB Avalanche Center 2020-21 Observations

Date of Observation: 01/09/2021
Name: Ben Ammon

 

Zone: Southeast Mountains
Location: Snodgrass
Aspect: North, North East, East
Elevation: BTL

 

Avalanches: Starting to be able to ski trigger Loose Dry on steep North-facing rollovers.
Snowpack: No propagating test results, but we observed a couple localized, stubborn collapses in previously untraveled terrain. One triggered by the fourth person in the track, and a few triggered by repeated stomps in the same spot. Upper snowpack continues to lose strength.

 

Washington Gulch Coneys Area

CB Avalanche Center 2020-21 Observations

Date of Observation: 01/09/2021
Name: Evan Ross

Zone: Southeast Mountains
Location:
Aspect: North East
Elevation: 9,700 to 10,800

Weather: Partly Cloudy, light winds. Funny seeing overcast skys and maybe a couple flakes over Mt CB and clear sky over the Ruby Range. How often does that happen?

Snowpack: The early December weak layer is widespread in the terrain. While slabs above that weak-layer are specific to cross-loaded terrain at lower elevations, or the lee sides of ridge-lines at NTL elevations. Not all terrain features with those common characteristics hold a slab, so you could argue that the slab is isolated in the terrain. Isolated and Stubborn…

We observed one collapse in a flat area. Otherwise no obvious signs of instability. Lots of tracks through all sorts of terrain features in Coneys and previous high traffic area. More ski tracks are also showing up in areas slightly further up valley that get a little less traffic. Still a few features of potential concern, otherwise all those tracks didn’t produce any results.

A few pits on a ENE aspect at ~10,600ft and on a 33-degree slope. Produced: SC fracture results on small column CT tests, and ECTN results on larger column tests, failing on 12/10. This location was sheltered from the wind and held a faceting 4F- slab over the early December facets.

Cracks & Collapsing in Washington Gulch

CB Avalanche Center 2020-21 Observations

Date of Observation: 01/08/2021
Name: David Bumgarner

 

Zone: Southeast Mountains
Location: Washington Gulch
Aspect: North, North East, East
Elevation: 9800 – 10800

 

Avalanches: None Observed
Weather: Temp: mid 20’s
Sky: Clear
Wind: Calm
Precip: none
Snowpack: We toured past the Coney’s Ski area and got multiple shooting cracks and collapses on steeper terrain features, upper 20 degree features and even a couple in flat areas. All of these areas had not seen much traffic (probably none) this season. Still feels tender out there! HS ranged from 70cm to 85cm in areas probed.

 

Photos:

Rotting Slabs

CBAC 2020-21 Observations

Date of Observation: 01/08/2021
Name: Jack Caprio & Jared Berman
Zone: Southeast Mountains
Location: Snodgrass to the east river
Aspect: North, North East, East
Elevation: <10,000′

Avalanches: None observed.

Weather: Clear, warm, and calm.

Snowpack: We traveled on primarily NE and E facing aspects up to about 10,000 feet. The lower in elevation we went, the less of a slab we found. Near the east river valley bottom, on a NE aspect, the snowpack consisted of about 50-70 cm of F hard cohesionless, faceted snow. Very weak. The only areas we were able to find a slab below 9,500′ was on isolated, exposed, ridgelines, where previous winds had drifted snow into a firmer slab about 5-20 cm thick.

A bit higher in elevation, still below treeline, we were able to find somewhat of a slab remaining on top of the 12/10 interface. That being said, the slab was 4F to F hardness, bottom to top, and seems to be losing strength as the days go on. A propagation saw test on the 12/10 interface produced an uninterrupted propagation to the end of the column. PST (29/100) End.

In the areas closer to town with a thinner snowpack, the persistent slab structure on shady aspects below treeline is becoming more difficult to find. With dry weather in the forecast after tomorrow, I expect the slabs to continue to rot away.

 

Photos:

Reno Divide

CB Avalanche Center 2020-21 Observations

Date of Observation: 01/08/2021
Name: D K

Zone: Southeast Mountains
Location:
Aspect: South, South West
Elevation: 11k

Avalanches: One fresh looking D2 off a southeast aspect of Hunter Hill.

Weather: Bluebird. Winds around 15 ATL
Snowpack: Initiated several collapses while setting a skintrack and skiing down in the vicinity of the track on S and SW aspects near treeline. Collapsing and cracks went up to 40′ on the largest. HS was about 80cm in sheltered areas and was punchy and unsupportive about 20% of the time

 

Photos:

cold snow, some crust

CB Avalanche Center 2020-21 Observations

Date of Observation: 01/08/2021

Zone: Northwest Mountains
Location: End of Washington Gulch
Aspect: South
Elevation: 10,000-12,000

Avalanches: Older natural on Baldy (previously reported)
Weather: sunny, low 20’s up high out of wind. Slight breeze on top. No snow transport.
Snowpack: Variety of depths as we skinned up maxing out at approx 120 cm on a below treeline south facing low angle slope. Small steeper and shallower S and SW pockets below treeline had a sun crust. Majority of the snow in protected areas was soft and awesome. Climbing the ridge between south and southeast bowls also varied in depth with new, wind loaded snow sitting on a slick and very firm surface in some spots. South facing bowl had a hint of a crust on steeper portion of descent (pole punched through the pack on one pole plant) that turned into cold pow once angle diminished. Partner found softer snow on eastern tilt of the south bowl. Ski pen 6 inches.

 

Good adventure in bad snow…

CB Avalanche Center 2020-21 Observations

Date of Observation: 01/08/2021
Name: Travis Colbert

 

Zone: Southeast Mountains
Location: Farris Creek
Aspect: South, South West, West
Elevation: 9,000-12,200

 

Avalanches: Old debris from the summit of Double Top N, in NE terrain. No new avalanches observed.
Weather: Blue sky, very little wind. Zero degrees in the AM, felt quite warm in the sun as we ascended…
Snowpack: Pretty much terrible. Ran the full spectrum between breakable crust to bottomless facets. Pretty much everything except supportable, soft snow. Large, widespread surface hoar. A little bit of supportable crust on steep south facing slopes where the snow was shallow (10cm); on those same slopes with deeper snow, punchy and weird, with shallow wind slabs just below the ridges. HS ranged from 0 – 85cm, with the average being 45 – 85cm. Had the opportunity to down climb a little maroon formation where the HS was 0. Also had the opportunity to perfect what I am calling the rocking side-slip in a shallow gully where the crust was particularly breakable and the baby aspens were especially tight. Finally, got the chance to wallow through the deepest and least supportable snow for that last mile or so along Farris Creek, back to our skin track. Exposed a pocket gopher when I punched through into the stream near the bottom; he/she seemed terrified. All in all, a good adventure in bad snow. The skin track is in if anyone wants to give it a whirl and ski a different aspect, or the same ones we did if my description was compelling.

 

Weak snowpack, still collapsing

CBAC 2020-21 Observations

Date of Observation: 01/08/2021
Name: Zach Guy

Zone: Southeast Mountains
Location: Mount Emmons
Aspect: North East, East
Elevation: 9,000 to 11,200 ft

Avalanches: Intentionally skier triggered a few small loose dry avalanches entraining the top 6″ of faceted surface snow. They ran about 600 vertical feet.
Weather: Few clouds, calm winds, mild temps above the inversion.
Snowpack: Still getting abundant collapses while breaking trail in untrafficked terrain. Persistent slab structure was about 18″ thick on average. Below ~10,000′, the slabs are so weak and faceted that the collapses only radiating a few yards (on northeast aspects). On east aspects at these lower elevations, we got a few collapses that propagated up to 20′ or so where there is a crust at the 12/10 interface helping to drive propagation. Avalanches at this elevation would be quite small and fairly isolated.
Above about 10,000′, the slabs get stiffer (up to 1F-). Collapses require a stomp or two, but they radiate across entire clearings (which were 50 feet or less where we traveled). Moderate propagating results in stability tests.
The snow surface continues to grow weaker. Large grained surface hoar is widespread except in wind exposed features. Near surface faceting is prevalent, and shallow facet sluffs are easy to trigger. Slopes that have previously avalanched (of which there are many), have an even weaker snow surface due to their shallow depths and stronger temperature gradients. The ones we poked at have an old bedsurface crust below all of the weak junk, which will make for an even more dramatic hardness difference when these layers get buried.

 

Photos: