Date of Observation: 12/24/2022
Name: Zach Guy and Eric Murrow

Zone: Southeast Mountains
Route Description: Cement Creek and Upper Brush Creek near Pearl Pass, up to 12700′ on various aspects.

Observed avalanche activity: Yes
Avalanches: A handful of previous hard slab avalanches from the arctic blast, D1 to D2, on heavily drifted slopes, generally E to S NTL.
Weather: Calm to light ridgetop winds. Mostly cloudy with periods of light snow. 1″ to 2″ of new snow since yesterday.
Snowpack: The Cement Creek valley floor was not as heavily wind impacted as what I’ve seen in the East River and Slate River corridors. The snow surface remains soft and weak below treeline, ~1mm facets. Once we climbed to near and above treeline, the snowpack got blasted. Snow surfaces are heavily wind affected, ranging from sastrugi to wind board to hard slab. The inch or two of fluffy new snow with no wind affect is a notable potential weak layer to monitor, especially if it facets over the next few days. It’s very low density resting on top of firm, wind hardened surfaces and there was minimal wind drifting it around, so it’s widespread at the moment.
No signs of instability today, though we weren’t messing around on the most suspect, windloaded slopes.

Date of Observation: 12/23/2022
Name: Irwin Guides

Zone: Northwest Mountains
Route Description: Irwin Tenure, East Barkmarker to Sunny Shoulder zone.

Observed avalanche activity: Yes
Avalanches: Triggered two additional D2s w/ HE. Same character as yesterday, running on 6-8″ of FCs.
Hollywood & Vine HS-AE-R2-D2-O FC (35cm x 20m x 100m)
Land of the Lost HS-AE-R2-D2-O FC (35cm x 15m x 75m)

Date of Observation: 12/23/2022
Name: Eric Murrow

Zone: Southeast Mountains
Route Description: HWY 135 avalanche obs on Whetstone

Observed avalanche activity: Yes
Avalanches: Three natural avalanches from the wind event above treeline.
Weather:
Snowpack:

Date of Observation: 12/23/2022
Name: Zach Guy

Zone: Southeast Mountains
Route Description: Roadside obs near CB.

Observed avalanche activity: Yes
Avalanches: D1 to D1.5 wind slabs in Racoon Basin and on small slopes near town from the wind event. See photos.

Date of Observation: 12/23/2022
Name: Zach Guy

Zone: Northwest Mountains
Route Description: Baxter Basin and Cascade Mtn, traveled on north, east, and south aspects to 11,700′

Observed avalanche activity: Yes
Avalanches: Nothing new today. A handful of small wind slabs at all elevations and one potentially larger avalanche off of the Shield on Emmons appear to have run during the arctic blast.
Weather: Few clouds, light winds, mild temps.
Snowpack: As is often the case with these extreme wind events, the terrain got ravaged and there appears to be far more wind erosion than loading from Wednesday night’s event. Lots of sastrugi and raised tracks on all aspects. Winds eroded down to the early December graupel layer in areas, which was buried about 50 cm deep a few days ago. Of course, there are some terrain features that caught the drifting snow and formed hard slabs, most commonly abrupt concavities or rollovers. Ski cuts and snowmobile cuts on numerous of these suspect features produced minimal signs of instability; one slope cracked. Probably the best news from all the devastation is that the near-surface facet layer that was quite weak and soft on the surface a few days ago has been destroyed in many areas because of the wind event. I found it still preserved in very sheltered trees below about 5″ of recent snow, and below sun crusts on southerlies where the winds hadn’t stripped the crusts away.

Date of Observation: 12/22/2022
Name: Eric Murrow

Zone: Southeast Mountains
Route Description: visible natural avalanches from town of Mount CB

Observed avalanche activity: Yes
Avalanches: Natural avalanche on East Bowl of Gothic and two on southeast aspects of Avery Peak.
Weather:
Snowpack:

Date of Observation: 12/22/2022
Name: Irwin Guides

Zone: Northwest Mountains
Route Description: Irwin Cat Ski Tenure

Observed avalanche activity: Yes
Avalanches: Two remotely-triggered avalanches ran sympathetically in near treeline southeast terrain.
Weather:
Snowpack:

Date of Observation: 12/22/2022
Name: Ben Pritchett

Zone: Southeast Mountains
Route Description: natural avalanche observation from Town of Crested Butte.

Observed avalanche activity: Yes
Avalanches: Natural R2D2 avalanche near treeline on Mount Emmons.
Weather:
Snowpack:

Date of Observation: 12/22/2022
Name: Eric Murrow

Zone: Southeast Mountains
Route Description: North through east slopes below Snodgrass Trailhead down to the East River.

Observed avalanche activity: Yes
Avalanches: Observed one natural avalanche from overnight on a well-drifted northeast slope below treeline and remotely-triggered two slabs on northeast slopes below treeline. All three were D1.5 and broke at the old, faceted snow surface prior to wind event.
Weather: Decreasing cloud cover throughout the day and reduction in wind speeds by late morning. New snow accumulation roughly 4 inches, but hard to say given the impressive wind event.
Snowpack: We went hunting for fresh slab formation below treeline on shaded aspects. Each time we found a fresh, hard wind deposit the slab collapsed and cracked. On two steep features, avalanches released in the upper snowpack around 1 foot deep on average, but some portions of crowns exceeded 2 feet. The distribution of fresh surface slabs seems fairly isolated below treeline, but touchy to the weight of the person when encountered. Faceted grains in the weak layer were around 1mm in size. Many nearby slopes with similar aspects were scoured without recent wind loading. A smooth, lens shape and hard surface made it fairly easy to identify sensitive wind drifts.