Observations

Date of Observation: 11/19/2021
Name: Evan Ross

Zone: Northwest Mountains
Route Description: Mt Owen

Observed avalanche activity: No
Avalanches: No recent avalanche, just the old stuff from a week ago.
Weather: Overcast sky. Trace of new snow, maybe a 1/4 inch! We mostly encountered calm winds, but there were some strong looking gusts blowing through the wind tunnels like near Green Lake.
Snowpack: The most notable observation was finding buried surface hoar from today’s snow. First happened to notice at about 12,500ft on a steep NE facing slope. The SH at that spot was 1cm tall under the trace of new snow. Continued to find the SH up to the ridgeline, and didn’t check on the decent. The SH was sitting on top of NSF, junk on junk.

Nothing notable to talk about below about 11,500ft. At those lower elevations the snowpack was shallow, but thankfully still supportable to keep the skis off the ground.

Above that elevation the snowpack continued to grow in depth and provided some surprisingly nice and soft ski turns. The best travel advice was keeping an eye out for those old thicker snow drifts, on northerly and easterly facing slopes, where maybe you could collapse a slab into weak snow below as you transitioned from the fatter snowpack to a thinner snowpack. In the end we didn’t find something that we chose to avoid. Feeling snow structure with a ski pole through the terrain didn’t show a consistent strong over week layering or significant, abrupt changes in hardness between those layers. Any thin interfaces would have been missed. Boot pen was around 35cm and ski pen averaging around 10 to 15cm.

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Date of Observation: 11/19/2021
Name: Zach Guy

Zone: Southeast Mountains
Route Description: Biked out to the end of West Brush Creek Road to document snow coverage

Observed avalanche activity: No
Weather: Overcast, a few snowflakes fell.
Snowpack: It would be very hard to find a slope with enough snow to produce an avalanche in this area. Maybe a small drift in the alpine. Below treeline, there is sufficient coverage on northwest to northeast aspects for fairly continuous weak layer formation. Other aspects are generally too patchy or bare. Above and some near treeline slopes have continuous coverage on east aspects and some windloaded southeast features as well.

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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

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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.

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Date of Observation: 11/16/2021
Name: Zach Guy and Eric Murrow

Zone: Northwest Mountains
Route Description: Redwell Basin. Traveled on northerly aspects to 12,000 ft.

Observed avalanche activity: No
Avalanches: Conducted a crown profile of a previously reported slab avalanche in Redwell Basin. The avalanche broke as a hard slab on 2mm facets near the ground, up to 5 ft deep on a windloaded bowl below a cliff band. We measured debris piles up to 9 feet deep. See photos.
Weather: Few clouds increased to overcast. Moderate swirling winds in the basin with strong gusts and periods of blowing snow. A short pulse of light snowfall passed this afternoon.
Snowpack: Below 10,000 feet, the snowpack is moist and less than 6″ deep. Above that, the snowpack transitioned to unsupportive facets, 1 to 2.5 mm in size, generally fist hard, and less than 2 feet deep. In short, it’s a rotten, sugary mess that will be a serious weak layer issue in the future. Previously wind loaded terrain is the only place where we could find any kind of slab. We experienced a couple of shallow, localized collapses in a wind drifted ravine. Otherwise, we traveled in weaker, trapdoor snow with no signs of instability, just dodging sharky rocks.

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Date of Observation: 11/15/2021
Name: Zach Guy

Zone: Northwest Mountains
Route Description: Upper Peeler and Oh-Be-Joyful Basin. Traveled on a variety of aspects from 10,000 to 12,000 ft.

Observed avalanche activity: Yes
Avalanches: Nothing new except a few harmless wet loose sluffs from the last couple days on steep southerlies. Noted a few more previously undocumented D1.5 to D2 sized naturals that ran during last week’s cycle.
Weather: Warm, clear skies, light winds.
Snowpack: No signs of instability. A couple of stability tests on east aspects produced non-propagating results on the Nov 9 crust/facet layer, down 14″ to 18″. This layer appears to be gaining strength compared to pits in similar locations last week. Total snow depths near and above treeline average 3 to 4 feet on shady aspects, and a foot or less on sunny aspects. Snow surfaces vary widely, from hard wind board and sastrugi on wind-affected slopes, wet grains on SE to SW aspects, and surface hoar and/or near surface facets in wind-protected, shady cirques.

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Date of Observation: 11/12/2021
Name: Eric Murrow

Zone: Northwest Mountains
Route Description: This observation was texted to CBAC from a group that was on top of Schuylkill Ridge.

Observed avalanche activity: Yes
Avalanches: Recent avalanche in Redwell Basin on Mount Emmons.  Northeast aspect above treeline.

Weather:
Snowpack:

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5005

Date of Observation: 11/12/2021
Name: Eric Murrow

Zone: Northwest Mountains
Route Description: Poverty Gulch underneath sunny side of Mineral Point over towards Angel Pass

Observed avalanche activity: Yes
Avalanches: Observed one recent natural avalanche below the summit of Augusta. Big enough to carry but not bury a person.
Weather: Strong winds in the morning relentlessly transported and stiffened snow near and above treeline. Winds subdued some in the afternoon. East and southeast aspects appeared to receive the most continued loading.
Snowpack: We ascended terrain facing southeast through east through northeast to 11,900′. Storm totals reached up to ~18″ near treeline (hard to measure as all terrain traveled was open and heavily affected by the wind). Dug a test profile on a drifted southeast feature at 11,000 feet with 3 feet of drifted snow resting on a melt/freeze crust without any result. A test profile on a north feature at 11,900′ showed moderate propagating results at the new/old interface which consisted of 1mm facets (see image). The slab was around 50cm thick and 4finger hard. Immediately following the test profile the slope collapsed as we walked away.  These test results and signs of instability steered us towards safer, lower angled options.

We moved through many drifted features that faced east and southeast looking for Wind Slab formation and found two locations that shot cracks up to 75 feet. The most reactive places were generally the stiffest and most supportive drifts.

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Date of Observation: 11/12/2021
Name: Zach Guy

Zone: Northwest Mountains
Route Description: Traveled on south to east to northeast aspects on Owen to 12,800′

Observed avalanche activity: Yes
Avalanches: A couple of small wind slabs ran today on east aspects above treeline, breaking in just today’s drifted snow. Several large slab avalanches ran off of NE and E aspects of Mt. Owen during the midweek storm. These all appeared to fail on or near the storm interface, about 18″ to 24″ deep. Some of these failed across terrain and in locations that aren’t typical for wind slabs…hinting at our developing persistent slab problem. See photos.
Weather: Strong northwest winds and active blowing snow this morning at all elevations. Winds transport died down this afternoon as scattered clouds developed. No recent precip.
Snowpack: We measured settled storm totals from the midweek storm up to 20″ in sheltered terrain. Significant fresh drifting occurred last night, with new 4F drifts up to 18″ thick. Snow depths on easterly aspects were 4 to 5 feet. We did not observe any signs of instability underfoot apart from some minor localized cracking in fresh drifts. A stability test on an east aspect ATL produced moderate propagating results below a 20″ soft slab, failing in 1mm facets below the 11/9 melt-freeze crust (See photo).

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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.

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