Evans Basin

CBAC2020-21 Observations

Date of Observation: 12/30/2020
Name: Eric Murrow

 

Zone: Northwest Mountains
Location: Evans Basin steep easterly shots
Aspect: East, South East, South
Elevation: 9,500′ – 11,200′

 

Avalanches: A couple of avalances in steep southeast terrain in Red Lady glades – near treeline type features. Look like storm slabs running on the old crust. Likely failed very early AM of 29th.
One D2 at the very end of Moonscape Ridge by Evans basin – ENE-facing very drifted BTL feature
Weather: Ugly cold at valley bottom in the morning, but comfortable temps near and below treeline in the sun. No snow transport observed on nearby high terrain.
Snowpack: Solar radiation moistened the snow surface on SE, S, and SW slopes up to 11,200′. Made for interesting breaker-crust skiing at 3pm once it started to refreeze. Relentless collapsing on low-angled terrain on the ascent. Lots of collapses on flat ridgeline above steep east-facing slopes but very little cracking and no resulting avalanches, hmmmm. Skied down a short steep east-facing slope without result, but probing sure confirmed the suspect structure below. Dug a couple of test profiles checking on SE facing features to see if the crusts below the new slab is a potential Persistent Slab problem; slab seems not quite cohesive and heavy enough to cause an issue at locations traveled up to 11,200′, BUT a disconcerting double-crust setup exists below the slab. Recent storm snow was around 30 – 35cm thick but still Fist to Fist+ hard and bonding poorly to the crust below (see photo). On collapse ran 100+ feet and shot cracks across a tiny NE-facing slope down to the 12/10 interface; upon inspection Surface Hoar (~5 – 8mm) was found below the recent storm at the likely 12/22 interface. Easily ID this interface with shovel tilt’s tests.

Photos:

 

Gothic obs

CB Avalanche Center2020-21 Observations

Date of Observation: 12/30/2020
Name: Alex Tiberio

 

Zone: Southeast Mountains
Location:
Aspect: North East
Elevation: 10,500

 

Avalanches: A couple fresh naturals ran today near the snodgrass gothic saddle sometime between 10 and 2 and saw another older slide below gothic road closer to the snodgrass trailhead
Weather:
Snowpack: Talkative. Large collapses if going off the ski track

 

Photos:

frequent shooting cracks & collapses RLG

CB Avalanche Center2020-21 Observations

Date of Observation: 12/30/2020
Name: jeff banks

 

Zone: Southeast Mountains
Location: RLG to Gravel Pit
Aspect: East, South East, South, South West
Elevation: 9,400-12,000

 

Avalanches: 4 older avalanches from ~10,800-11,200. from tail end of storm around 1-2 inches of snow on the old debris/bed surface in the “W” bowl between standard skin track easy glade line.
Weather:
Snowpack: Barking snowpack. Can’t move without Small to Large collapses skiing in less disturbed areas. Shooting cracks 3-15m NTL & BTL SE-S-SW all the way down to Kebler road. Slopes cracking up to ~38* but not releasing. Seeing some aggressive terrain choices out there for how vocal the snowpack is. Via con dios amigos.

 

Purple People Eater

CB Avalanche Center2020-21 Observations

Date of Observation: 12/30/2020

 

Zone: Northwest Mountains
Location: Slate drainage
Aspect: East, South East
Elevation: ATL

 

Avalanches: A lot of natural avalanches, huge on purple and one on gothic.
Weather:
Snowpack: Shooting cracks and a couple large collapses while breaking trail.

 

Photos:

Nasty natural

CB Avalanche Center2020-21 Observations

Date of Observation: 12/30/2020
Name: Sam L

 

Zone: Northwest Mountains
Location: Upper slate
Aspect: North, North East
Elevation:

 

Avalanches: Observed a new large natural in Baxter basin.
Weather: Cold and clear. Traveling uphill on southerly slopes was very warm but with little discernible change in snow surface.
Snowpack: Traveling up hill through north facing terrain produced several large and rumbling collapses with shooting cracks running hundreds of feet (see photo). Skiing southwest terrain we traveled through 12 to 15 inches of consolidating storm overlying a stout sun crust.

 

Photos:

Morning avalanche obs

CBAC2020-21 Observations

Date of Observation: 12/30/2020
Name: Zach Guy

 

Zone: Northwest Mountains
Location: Scarp, Peeler, and Gothic
Aspect: North East, East
Elevation: ATL

 

Avalanches: See photos. Several slab avalanches D2, maybe up to D2.5 on E and NE aspects ATL that likely ran early yesterday.

 

Photos:

Avalanche obs on Whetstone from the highway

CBAC2020-21 Observations

Date of Observation: 12/29/2020
Name: Eric Murrow

 

Zone: Southeast Mountains
Location: Whetstone Mountain
Aspect: North East, East
Elevation: near and above treeline

 

Avalanches: Observed natural avalanche on Whetstone at 945am.
Several avalanches on far southern end near CB south on east and northeast aspects near treeline, D1-D2
D2 avalanche in Barcelona Bowl NE aspect above treeline
D2 in Lucky Boy Bowl NE aspect near treeline

Several of these avalanches appeared to be shallow storm slabs that “stepped down” into deeper persistent weak layers

Photos:

 

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: