Observations

Zone: Southeast Mountains

Location: Snodgrass/Gothic saddle

Date of Observation: 12/11/2020

Name: Alex Tiberio

 

Subject: Snowpack ripe for failure

Aspect: North East

Elevation: 10500

Avalanches:

Intentionally triggered a D2 Storm Slab on a NNE facing slope. Released about 20 ft below a ski cut. Propagated 20 ft wide running about 500ft downhill. Phone died, couldn’t get pictures.

 

Weather: Snowing on and off throughout the morning. Sometimes heavy. 6” new snow in gothic. About 8” on the snodgrass/gothic ridge line

Snowpack: Weak. Some preserved surface hoar below the storm snow. Facets to the ground below that. Easy the produce spiderwebbing shooting cracks on More northerly facing slopes

Photos:

 

Zone: Crested Butte Backcountry
Date: 12/11/20
Name: Jack Caprio/ Zach Guy

After a very long stint of high pressure, we finally have a storm system making its way into the Crested Butte area. Take a look at the weekly weather/ snowpack summary to see how our snowpack stacks up before this new loading event.

Zone: Southeast Mountains
Date of Observation: 12/11/2020
Name: billy barr
Subject: Gothic 7am Weather Update

Weather: Light snow starting around 9 p.m. and going off and on overnight but picking up a couple hours before sunrise. Now 3″ new snow with water 0.21″ and snowpack 12½”. No wind and currently obscured and snowing lightly. Yesterday’s high was 34ºF and the current is the low of 17ºF. billy

Zone: Southeast Mountains
Location: Cement Creek
Date of Observation: 12/11/2020
Name: Cosmo Langsfeld

Elevation: 9250’
Weather: ~1.5” of new snow as of 5:30am.

Zone: Southeast Mountains
Location: East side of Carbon Peak
Date of Observation: 12/10/2020
Name: Bo Torrey

Aspect: North, North East, East, South East, North West
Elevation: 10,800-9200′

Weather: Overcast skies. Calm winds.

Snowpack: South aspects were bare ground up to 12,000 ft. Snow depths on northerly slopes averaged about 30-40cm. On SE facing slopes the snow had consolidated down to just a few inches and coverage was thin but the snow was supportable and made for more predictable turning conditions. On east, north, and northwest facing slopes, I found a mix of crust and facet layers with varying levels of thickness and support. On the surface, there was a subtle crust with facets directly below it, followed by another thicker and more supportable crust 15-20cm beneath the surface. On due north-facing slopes, the crust was less noticeable but still existent on slopes near treeline. The snowpack on due north was entirely faceted and unsupportive.

Photos:

Zone: Southeast Mountains
Location: Wolverine Basin
Date of Observation: 12/10/2020
Name: Zach Kinler and Jack Caprio

Subject: The Greybird sings

Aspect: North, North East, East, South East, North West

Elevation: 9,000-11,000′

Avalanches:

No new avalanches observed

Weather: High-level cloud cover has drifted in after another cold night. This kept daytime temps cool. Light southerly breezes at valley bottom.

Snowpack: Thin snowpack with weak surfaces, nothing too new to report there. Got a few looks at NW aspects below treeline where coverage is thin but continuous and just as weak as SE-E-N with large grain facets resting on a soft windboard in open areas and facets to the ground in sheltered terrain.

 

Photos:

 

Zone: Southeast Mountains
Date of Observation: 12/09/2020
Name: Evan Ross

Snowpack: After a long dry spell for the end of November and the start of December, we could boil a snowpack summary down to something fairly simple. If the terrain was white with snow on December 9th, then those slopes will have a weak foundation for the next round of snow and building snowpack to come. Not all the current snow coverage will be the next persistent weak layer, but the vast majority will be. So keep it simple, where we had snow coverage around ~12/9, is where we can expect the next persistent Slab Avalanche Problem to begin building. Of course, we need it to start snowing again. Please start snowing again.

There is less terrain not on the potential problematic list, so let’s look at those slopes. Below Treeline SE, S, and SW have bare ground. Near Treeline, those same slopes have a variable patchwork of snow. Above Treeline southerly facing slopes have the best coverage in the Northwest Mountains, and more patchy snow coverage in the Southeast Mountains. On northerly facing slopes below 8,500ft the snowpack is either very thin or patchy. Just about everything else had continuous snow coverage, or at least much better coverage than what was listed earlier.

The pictures below document some of the slopes that had bare ground or patchy snow coverage on or around 12/9.

 

 

Zone: Southeast Mountains
Location: West Brush Creek Road towards Coffee Pot Pass
Date of Observation: 12/07/2020
Name: Eric Murrow

Subject: West Brush Creek

Aspect: North, North East, East, South East, South, South West, West, North West

Elevation: 8,900′ – 12,250′

Avalanches: Two small loose avalanches in steep terrain below treeline. Looked like east-facing rock bands may have shed small amounts of snow from solar warming onto slopes below.

Weather: Gorgeous. Mild air temperatures with very little wind below ridgetops. Full sun.

Snowpack: Shallow conditions throughout West Brush Creek. Snow volumes looked to decrease as we traveled east towards the head of West Brush Creek drainage even as elevation increased. The wind has affected most snow surfaces near and above treeline. Protected below treeline slopes that avoided the worst of the wind were around 40cm of faceted fist-hard snow. Oversnow travel was difficult and required unusual routes to stay on snow and avoid scree and bushes. There is very little terrain in this area that is viable for downhill recreation…so we just went for a tour following the valley bottom to document snow coverage in the area. Most terrain was well faceted with thin windboards capping the surface on slopes near and above treeline. We got one mentionable collapse of a 2-3 inch thick, pencil-hard windboard sitting on fist-hard 1-1.5mm facets at 12,000′ on an east-facing feature – cracks propagated around 75 feet.  Faceted snow was in the 1-2mm range on west through north through east-facing slopes and fist-hard. Southerly slopes were often melted back to dirt or melt/freeze crust sitting on the ground.

 

Zone: Southeast Mountains

Location: West Brush and Twin Lakes basins

Date of Observation: 12/07/2020

Name: Zach Guy

 

Subject: One good turn

Aspect: North East, South East, South

Elevation: 9,000 – 13,000′

Avalanches:

Came across an old natural persistent slab crown and debris, 2′ to 3′ thick, D1.5 in size, below the apron of a couloir on a NE aspect. Looks like it ran last storm, about 2 weeks ago.

Weather: You guessed it.

Snowpack: Checking out the snow structure in some less frequented areas east of town: equally weak and shallower than terrain to the west. Snow depths in shaded, wind protected terrain are about 12″ to 15″, fist hard 1.5 – 2.0 mm facets throughout, unsupportive to skis. Near and above treeline slopes show more beating from previous winds; the snow surface is textured and varies from pencil hard wind board to fist hard facets and everything in between. On the southern quadrant of the compass (SE to SW), the snowpack is patchy to just wind drifted features at high elevations and mostly all melted away at low elevations. We traveled almost exclusively on southern aspects or high elevation terrain and saw no signs of instability. Small, shaded rollovers below treeline easily sluffed. I noticed a radiating collapse in flat terrain from a suncrust on the snow surface collapsing on facets below. No surface hoar around here except in creek beds.

Photos:

Zone: Southeast Mountains

Location: Climax Chutes

Date of Observation: 12/04/2020

Name: Zach Guy

 

Subject: More of the same…dry loose avalanches

Aspect: North East, East

Elevation: 11,300′

Avalanches:

Intentionally triggered about 8 dry loose avalanches from ridgeline, generally D1.5 with a few up to D2 in size. The sluffs started in the top 8″ to 10″ of faceted snow and plowed deeper as they ran further. Estimate they ran about 1500′ to 2000′ vert.

Weather: Clear, mild temps, calm winds.

Snowpack: Same old story. Weak faceted snow throughout the snowpack, generally fist hard. Decaying surface hoar in the top few inches of the snowpack produced some minor cracking where there were 2″ wind drifts. Snow gains a little cohesion as you gain elevation, and also is a bit more supportive in sparse trees compared to open chutes. The most reactive sluffing is in open terrain without tree cover. We avoided steep shady terrain because of both pushy sluffs and rock hazards and returned via a low angle ridgeline.

Photos: