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.

Date of Observation: 12/22/2022
Name: Travis Guy

Zone: Southeast Mountains
Route Description: Gothic

Observed avalanche activity: Yes
Avalanches: Wind slab on a drifted rollover near Gothic. See photo.

Date of Observation: 12/22/2022
Name: Billy Barr

Zone: Southeast Mountains
Route Description: Gothic Townsite

Observed avalanche activity: No
Avalanches:
Weather: The worst type of weather- cloudy, only very light snow (1″ new 0.12″ water) and damaging strong wind, gusts at my station up to 50 mph but the station was set for snow and is protected from straight on wind. There has been a bit of clearing after sunrise and a bit of a decrease in wind though the temperature has slowly been dropping. Currently still 15-20 west wind gusting to 30 (probably 50 or more in open areas). Wind transport of snow is the biggest slide hazard. billy
Snowpack:

Date of Observation: 12/21/2022
Name: Eric Murrow

Zone: Northwest Mountains
Route Description: Washington Gulch Road to Elkton Knob and the southerly side of Baldy.

Observed avalanche activity: No
Avalanches: none observed
Weather: Around 3 inches of new snow by 3pm. Continuous light snowfall during the day amounted in very little accumulation. Most new snow fell overnight. Moderate WSW winds at ridge top, some gusts were strong.
Snowpack: While traveling through several drifted near treeline features, we produced cracking up to 15 feet in the storm snow. Cracks were in lower-density storm snow as most leeward features near treeline had stiff old snow surfaces from previous winds. Wind drifts up to 10 inches were observed immediately below cornices/terrain breaks but quickly diminished to just a few inches on a feature scale. I suspect you could have triggered small avalanches in the storm snow at upper elevations but the size would have generally been harmless to a person.
In sheltered areas facing the north half of the compass, the old snow surface was comprised of small grain facets, generally less than 1 mm, and looked weak enough to not tolerate significant loading before small avalanche activity begins.
I dug a single profile in a leeward northeast-facing feature at 11,300 feet to look at the basal facets. I chose to dig here as it would demonstrate a best-case scenario for improvement in basal facets as the depth was around 150cm with 125cm of slab resting above. The basal facets were 4-finger hard (softer end of 4-finger harness) and showed clear signs of rounding, but remain far softer than the hard, drifted slab above. It still appears possible to trigger an avalanche in basal weak layers where snow depths are variable leaving thinner slabs above the weak layer.

Date of Observation: 12/21/2022
Name: Zach Guy

Zone: Northwest Mountains
Route Description: Rec tour on Schuylkill Ridge

Observed avalanche activity: Yes
Avalanches: Skier triggered a handful of shallow, long running sluffs in the top 30 cm of soft, faceted snow.
Weather: Light snowfall all day. Light winds with moderate gusts this afternoon created periods of moderate blowing snow.
Snowpack: 2” new. Minimal signs of instability while breaking trail; one localized collapse near valley bottom. Most steep terrain that we rode on or near had avalanched earlier this month. Bed surfaces are weak and primed for repeat offenders. Surfaces are generally fist hard 1-1.5mm facets on northerlies and soft crust facet sandwiches on southerlies. No wind slab development yet where we were, but I could see plumes off of suspect terrain this afternoon