Zone: Crested Butte Backcountry
Date: 12/25/2020
Name: Jack Caprio
Along with our 12/10 weak layer/interface, we can now add wind loading and surface hoar to Santa’s naughty list. Check out the weekly recap of weather, snowpack, and avalanche activity to see how our snowpack is changing.
Date of Observation: 12/24/2020
Name: Eric Murrow
Zone: Southeast Mountains
Location: Anthracite Mesa – terrain features just up valley of Coney’s proper
Aspect: North East, East, South East
Elevation: 9,500′ – 10,800′
Avalanches: some evidence of moving snow in Rock Creek bowl on Baldy (southeasterly above treeline), but too far away to see any reportable details.
Weather: Cold morning at valley bottom, but temps warmed to a comfortable level by midday. Winds were light below treeline and at 10,800′ ridgeline. Blowing snow was visible on several high peaks but hard to say how much loading actually occured. Winds looked to be from N/NW loading terrain that faced south and east.
Snowpack: Traveled on heavily trafficked uptrack, but traveled out of this area for the descent and obs. Received two large collapses the ran 100+ feet on low-angled northeast aspects around 10,800′. Descended slopes in the 28 to 32-degree range with small steeper features immediately adjacent, but no collapsing or cracking while skiing down. Collapsing felt like it was less frequent but larger in size. Stomped above steeper features looking for a result from a safe location, but nada. Test profile continues to show up to 4-finger hard slab resting on fist hard 2mm facets with even larger grained snow at the ground (see photo). Snowpack still looks and talks like trouble in areas with median level snow depths, not the deepest snowpack around Crested Butte but more than the shallowest areas.
Date of Observation: 12/24/2020
Name: Zach Guy
Zone: Southeast Mountains
Location: Mount Emmons
Aspect: North, North East
Elevation: N/BTL
Avalanches: Ski triggered a few thin windslabs (5”-10” thick) breaking on the 12/22 near surface facets. Ski triggered a small persistent slab (16” thick, 12/10 interface) on a small terrain feature. Saw one fresh natural wind slab in Wolverine Cirque (D1.5)
Weather: Clear and calm
Snowpack: Widespread rolling collapses and shooting cracks while breaking trail in open terrain or aspen groves. Cracks radiated 50 to 100 feet on average, collapses were noisier than a similar location last week. Below treeline, the 12/10 interface is buried about 16″ by a F down to 4F slab. The 12/22 near surface facets produced some minor cracking in wind sheltered terrain, buried about 3″ or 4″ deep.
Photos:
The accident investigation from the Snodgrass avalanche incident on December 15, 2020 is available here.
We do our best to describe avalanche accidents to help the people involved and the community as a whole better understand them with the hope that it will help people avoid future avalanche accidents. Thanks to everyone who responded to this incident and helped improve the outcome, and thank you to the party involved for sharing their story to turn it into a learning opportunity for all of us.
Date of Observation: 12/23/2020
Zone: Southeast Mountains
Location: Anthracite Mesa
Aspect: East
Elevation: 10800
Avalanches: Visibility was fairly limited during most of our tour today. We weren’t able to get many solid views on surrounding mountains, thus unable to observe any recent activity on adjacent terrain. However, the views we were able to get of the west facing terrain on Gothic demonstrated the recent winds have stripped much of the snow in the usual spots and have cross loaded the other usual features.
Weather: Overcast with occasional periods of obscured sun. Variable winds, average winds during our tour was probably 10 mph with the highest gusts in the 20-30 mph range. Winds were cold and mainly out of the north. Light snow at times but minimal accumulation. Colder temps but not as cold as we anticipated. Probably a high of 10ish while we were out.
My partner and I were able to observe some of the old crowns and debris in the open terrain on Coney’s, which have previously been mentioned in recent observations, indicating that this particular terrain hadn’t yet completely filled in with recent snow and drifting. Fully aware of the heavy winds and recent snow (and recent accidents– rest in peace, JS), we had no intention of skiing anything with consequence. Out of curiousity though, on the first lap, we decided push up to the ridge to test leeward slopes which were clearly drifted and maintaining reactive slabs. Upon gaining the ridge through the timber, we immediately started putting weight on wind loaded slabs just below the ridgeline. Probing with our poles we found obvious differences in snow depth from the ridge proper to the leeward side of the ridge (approx. 25 cm–80 cm +). Intitially we weren’t able to produce any collapsing or cracking, but it was quite apparent the slab was there, regardless, and it was waiting for someone to ski through the perfect spot to trigger. After traveling up the ridge around 150′ we began to feel slightly stiffer snow and our pole probes proved the snow was getting deeper in the more open spots on the leeward side of the ridge, as compared to just a little lower on the ridge where it was slightly more protected. We eventually were able to trigger a slab on an obvious drifted feature, with minimal effort. The slab failed somewhere mid-snowpack, which one assumes would be the persistent weak interface(s) from early December. The slab moved with suprising energy but only traveled a few inches downhill. Slope angle where slab was triggered was around 30 degrees. Propagation wasn’t huge, probably fractured 30′ laterally. Regardless, we certainly could understand the the consequence of the potential avalanche in this terrain…not good. Also worth noting, as I skied first (in a much safer entrance), my partner felt and noticed a huge collapse, which we assume propogated the entire slope and would have entrained the slab mentioned above.
Not trying to be on a soap box or anything here, but this is a particular area which is always concerning to many. Coney’s/ Anthracite Mesa can be great skiing/ riding, don’t get me wrong, but I do feel this zone can present a false sense of security for some people. I usually wouldn’t post a huge observation like this, however, I think it’s important to reiterate everything CBAC is telling you. The backcounty is dangerous in Colorado and this season is certainly no exception. The snowpack is dangerous and unpredictable, and there are many complexities which can turn a fun day into a life or death situation. Please don’t ever assume things are safe when you are in avalanche terrain. Get home safe to your family and friends. Happy Holidays my friends and please be safe out there.
Snowpack: Dangerous, variable, and touchy.
Photos:
Date of Observation: 12/23/2020
Name: Andrew Breibart
Zone: Southeast Mountains
Location: Cement Creek (Deadman to Reno Divide Road)
Aspect: West, North West
Elevation: BTL
Avalanches: None.
Couldn’t see anything on Cement Mountain (north bowl).
Weather: mostly calm with spurts of light and moderate winds. Moderate winds lasted less than 1 minute transporting new snow from creek to adjacent hillslopes. Skies were obstructed. S-1 snowfall with no measurable accumalation.
Snowpack: Between 1 to 2 inches of new snow was on the ground. Total snow depth ranged between 12 inches and 28 inches (30 cm to 71 cm). Cracking occurred on all slopes explored:
1. above the road (15 to 20 degrees on East aspect near Deadman);
2.below the road (around 30 degrees on West aspect at switchbacks by Upper Cement Creek Road;
3. and in forested and open terrain away from the road (10,000 feet on W/NW aspect on slopes around 30 degrees). I had two collapses in treed terrain. Ski pen with skimo skis and 118 lb skier was 14 inches (36cm).
Photos provided.
Photos:
Date of Observation: 12/22/2020
Name: Travis Colbert
Zone: Southeast Mountains
Location: Coney’s
Aspect: North East
Elevation: 9,500-10,800
Avalanches: No avalanches that have not already been reported.
Weather: No avalanches that have not already been reported.
Snowpack: Upper snowpack is faceting out (again). Widespread (and very large) surface hoar. Lots of collapsing and cracking when travelling off the established skin track. Seems like any convexity over 35 degrees that hasn’t already slid would easily slide. Some small windslabs forming just below the ridgeline. Any slopes with the slightest S aspect have a soft crust.
Photos:
Date of Observation: 12/21/2020
Name: Zach Guy
Zone: Southeast Mountains
Location: Red Lady Bowl
Aspect: East, South East
Elevation: 12,200
Avalanches: Looked at the crown of a remotely triggered slab in Red Lady from earlier today (SS-ASr-R1-D1.5-O) on an east-southeast aspect ATL. The slab was 40 cm thick and failed on faceted snow between two thin crusts (12/10 interface). It appears as if the avalanche sympathetically released a smaller slide (D1) a few hundred feet away on an east aspect.
Weather: Clear and warm
Snowpack: Several rumbling collapses throughout the tour. A 30 degree, east facing test slope, at 10,300ft, also produced shooting cracks throughout the slope.
Photos:
Zone: Southeast Mountains
Location: Saddle to gothic road
Date of Observation: 12/20/2020
Name: JAFAR TABAIAN
Subject: Snodgrass
Aspect: North East
Elevation: BTL
Avalanches: Many natural and skier caused slides. Our ski route followed two tracks that led directly into skier initiated D1.5 R1 slide, looked like they skied out. We deviated the route and took a mellow line out. During which we remotely triggered a slide into a gully. Crown looked 12-18” from below (attached photo). My takeaway of the current conditions on Snod is to assume any convex rollover greater than 30 degrees will avalanche if it hasn’t already.
Photos:
Zone: Southeast Mountains
Location: Mt Emmons
Date of Observation: 12/20/2020
Name: Travis Colbert
Subject: A few feet off the skintrack…
Aspect: North East, East, South East, South
Elevation: 9,300-12,300
Avalanches:
Remotely triggered (intentional) ENE slope by taking two steps off the skintrack where the slope steepens and the trees thin. D1, but flushed through trees. Observed a natural D1.5 on an east-facing slope across Redwell basin.
Weather: Clear, steady WNW winds at the summit.
Snowpack: Fresh windslabs in RL bowl forming just below the ridge at the summit. Lots of collapsing off the skintrack along the ridge. Glades were recycled powder up high, becoming crusty down lower. Redwell basin looked thin and wind-hammered.
Photos:
