Date of Observation: 11/17/2021
Name: Eric Roberts

Zone: Northwest Mountains
Route Description: 10:00-17:00
Toured up Elk Creek towards Scarp Ridge and topped out at Mount Emmons to assess instability of upper elevations and familiarize myself with terrain. I conducted one test pit above treeline with results showing poor stability overall. I descended Elk Basin and followed my skin track back to the parking lot.
A mixed bag of ski conditions but great to get up high with this early season coverage.

Observed avalanche activity: No
Avalanches:
Weather: Few in AM trending to CLR in PM
Light westerly winds in AM in Treeline
Consistent, moderate NW winds above treeline and along ridgelines
36°F @ 9,580’ (10:00)
15°F @ 12,080 (14:30)
No Precipitation
No riming observed
Snowpack: My focus was to assess the early season snowpack instability in the alpine and potential problems that may arise with the next added load. Tests showed low strength, propagation propensity and poor stability overall. The buried graupel layer 43cm down was reactive in both small and large column tests snd very visible in profile.

9,560’-12,340’: .5mm Graupel is present on most sheltered snow surfaces which could be buried in future storms. 20-40cm of unsupportive snow exists in most shaded and sheltered locations with wind loaded areas having up to 200cm.

*See snowplow for details*
Red Flags: No cracking, shallow localized collapsing in wind drifted areas
No observed releases
No test slopes performed
Active snow transport on ridgelines around 12,000’ on Scarp Ridge and Ruby Ridgeline

Date of Observation: 11/17/2021
Name: Evan Ross

Zone: Southeast Mountains
Route Description: Denver to Gunnison

Snowpack: As we head into another period without a notable storm, here are some pictures to help keep track of the current snow coverage. There are a few key ingredients driving the current snow coverage. Elevation, aspect, and location.

Elevation: The valleys are dry. Snow coverage is most consistent above treeline along the spines of the mountain ranges. Many near treeline elevations are fairly dry, or have patchy shallow snow, except for the snow belts along the Ruby Range and Elk Mountain.

Aspects: Northerly and easterly aspects have the best coverage across the board. The Ruby Range of course has the best coverage around the compass when compared to the other mountains. The spine of the Elk Mountains also looked to have coverage on all aspects at upper elevations. Then as you got closer to Star Pass, Taylor Pass, and further east you could see west aspects becoming blown out and south aspects looking thinner or more patchy.

Location: The spine of the Ruby Range of course wins out for the best looking and most consistent coverage. The Spine of the Elk Mountains also had consistent coverage at its western end, then thinner or more specific located snow coverage as you moved further east towards Taylor Pass.

Date of Observation: 11/12/2021
Name: Ben Pritchett

Zone: Souteast Mountains
Route Description: Observations from near Crested Butte

Observed avalanche activity: Yes
Avalanches: Two small natural avalanches released on a pair of east to southeast facing-slopes above treeline. One broke in Coon Basin (east), and another off the saddle in Mt. Baldy’s southeast face.
Weather: Efficient wind transport this morning. Cinnamon weather station shows north northwest winds averaging around 35mph, with a peak gust to 70.

Date of Observation: 11/09/2021
Name: Eric Murrow

Zone: Northwest Mountains
Route Description: Northerly side of Purple Ridge. Ascended from the head of Slate River Valley.

Observed avalanche activity: No
Avalanches: None
Weather: Partly to mostly cloudy. Light winds and mild temperatures.
Snowpack: The goal of this trip was to look at old snow surfaces and observe faceting on shaded slopes at upper elevations. The past week of clear nights has slowly weakened and faceted the snow surfaced on most slopes on the north half of the compass. Grain size remains relatively small around .5-1mm (see photo). Northerly slopes above ~10,000′ are not going to bond well with incoming snow. I dug a profile in an area with the deepest accumulations this season; the oldest snow near the ground is well-faceted, but was moist and appears to be rounding (see profile). In general, the faceted surface appears to be of more concern for the incoming storm than the weak snow on the ground. Snow coverage is pretty continuous on northerly slopes above ~10,000′ and will be a weak layer to keep an eye on with snowy weather forecasted for the second half of the week.

Northerly slopes below -10,500′ often had a soft, faceted melt-freeze crust at the surface.

See additional photos for examples of snow coverage around the CBAC forecast area.  Sorry for the blurriness.

Photos:

Date of Observation: 11/04/2021
Name: Ben Pritchett

Zone: Northwest Mountains
Route Description: Parked at Schofield Pass, skied up Cinnamon Mountain’s NE bowl.

Observed avalanche activity: Yes
Avalanches: One large avalanche ran during the November 2 storm off Peeler Peak’s northeast face. This soft-looking slab avalanche broke around 800 feet wide and ran around 800 feet downslope. We saw a handful of small avalanches in the storm snow in very steep wind-drifted alpine terrain features.
Weather: Ridgeline Wind Speed: 5-10 mph
Ridgeline Wind Direction: NW
Wind Loading: None
Temperature: 28 F
Sky Cover: Clear
Depth of Total Snow: 65 cm
Weather Description: Balmy late fall day. Bluebird skies. Temperatures rose above freezing at 12,000 feet for around 2 hours. Valley bottom temperatures made it well into the 40’s.
Snowpack: Around a foot of snow fell on Tuesday, November 2 in this area.
On sheltered northerly-facing slopes, the storm snow sits on 2 or 3 dense and supportive old-snow layers. Below the new snow/old snow interface we found a thin layer of facets below a crust which could pose a problem as slabs develop on top of this structure, but it poses no concern at the moment.
Above treeline, these buried old snow surfaces are highly variable, so the recent storm snow sits on bare ground, glaze ice, stiff sun-hardened crusts, or dense old drifts.
On southerly-facing slopes, the storm snow settled to only a few inches, mostly resting on bare ground, or old, slick drifts from the late October storm. These sun-exposed slopes moistened by late morning.
We observed no cracking or collapsing. ECT’s did not propagate below the crust under the storm snow. We did get one ECTP near the ground where we found a sheltered slope with larger facets buried near the ground (see profile), but this structure appears isolated in the terrain.

Date of Observation: 10/30/2021
Name: Evan Ross

Zone: Southeast Mountains
Route Description: Cement Mountain

Observed avalanche activity: Yes
Avalanches: 2nd hand report of a small avalanche triggered by a herd of Elk crossing the slope. The avalanche appears to have release from a previously wind-loaded portion of the slope where the snowpack was deeper. Estimated N to NE aspect around 11,400ft.
Weather:
Snowpack:

Date of Observation: 10/27/2021
Name: Eric Murrow

Zone: Northwest Mountains
Route Description: Purple Ridge area

Observed avalanche activity: No
Avalanches: none observed, but limited visibility
Weather: Mostly cloudy skies with very light snowfall through 3pm. Moderate winds with strong gusts at ridge top from the northwest. Snow transport was visible across alpine terrain all day.
Snowpack: Storm totals ranged from 4 inches at valley bottom at 9,700′ to 11 inches at treeline. I traveled between 9,700′ and 12,000′ on east and northerly aspects. Below treeline I only found old snow beneath the recent storm on northerly aspects. All northerly slopes below treeline showed soft crusts and facets below the recent storm snow (see photo). Not enough new snow to form an avalanche problem on sheltered, northerly terrain below treeline. No cracking or collapsing.

I traveled on easterly aspects near and just above treeline and commonly found a stout melt/freeze crust directly on the ground with 10″ to 24″ of windblown storm snow resting above (see photo). I was able to produce a few cracks running up to 30 feet in drifted snow but cracks were shallow in just the top few inches of storm snow. Probing revealed a few isolated locations immediately below ridge top that had facet/crust combinations below the recent storm, but in this area, they were only found in old drifts.

Photos: