Gothic Weather

CBACCBAC Observations

Date of Observation: 12/07/2021
Name: Billy Barr

Zone: Southeast Mountains
Route Description: Weather obs from Gothic townsite.

Observed avalanche activity: No
Weather: And off we go. Sort of. Generally light snow starting after dark and stopping not long after midnight. There was 3½” new and water of 0.21″- a light 6% density. Wind early but calm much of the night. Currently cloudy with a few little breaks in the clouds, while no wind for now. Yesterday’s high was just 39F, the lowest high temperature in 11 days, and the morning low and current 21F. Snowpack is at 4½” but very uneven as is the case early in the winter. Really not much going on down here but given this winter it is a big deal. billy

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West and Northwesterly look around

CBACCBAC Observations

Date of Observation: 12/06/2021
Name: Eric Murrow

Zone: Northwest Mountains
Route Description: Westerly terrain near Elkton on Anthracite Mesa high point (Elkton Knob) . Traveled in near treeline elevation band on west and northwest aspects.

Observed avalanche activity: No
Avalanches: Pushed on a short but steep northwest-facing feature at 11,100 feet and got a very small facet sluff to run a short distance and entrain much of the shallow snowpack.
Weather: Thin, high clouds began to move in by midday. Generally light westerly winds with some moderate gusts.
Snowpack: I have not traveled across many westerly aspects over the recent dry spell so the goal of this trip was to check out some west through northwest features near treeline. All features just north of due west were very weak with just a thin melt-freeze crust or were fully dry. Snowpack ranged from 30 – 60cm deep. Surface Hoar was sporadically present on these windward slopes and generally around 5mm in size. As aspect rolled from due west to southwest, the snow surface went from a thin crust to presumably thicker crusts and then quickly to mostly bare dirt on southwest.

Photos:

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Mapping snow coverage in the Southeast Mountains

CBACCBAC Observations

Date of Observation: 12/05/2021
Name: Zach Guy

Zone: Southeast Mountains
Route Description: Driving tours the last two days, Gothic Road, Wash Gulch, near town, and Cement Creek to Reno Ridge

Observed avalanche activity: No
Weather: Sunny.
Snowpack: See sketch and photos. The southern half of the compass has mostly melted off to dirt or patchy coverage. Fairly continuous snow coverage on NW to N to NE aspects and high E aspects, apart from some brush or talus protrusion in certain areas. I didn’t travel much on snow, so surface characteristics are estimated based on previous observations. A few roadside handpits on shady aspects near and above treeline show very weak, striated facets and depth hoar throughout (2mm to 4mm). Most below treeline locations that I looked at had large surface hoar (>1cm) on flat or shady aspects. About as weak and ugly as it gets.

Photos:

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Purple Ridge

CB Avalanche CenterCBAC Observations

Date of Observation: 12/05/2021
Name: Kyle Juszczyk

Zone: Northwest Mountains
Route Description: Purple Ridge

Observed avalanche activity: No
Avalanches: None
Snowpack: We skied W aspects that leaned N from 11k to 11.5k and were able to find soft snow. There was a widespread sun crust on W-SW aspects up to 11.5k

Dug down at 11,500′ on a WNW aspect 40′ down from ridge line. HS: 105. Increasing hand hardness all the way down. No substantial weak layers, even at the ground. Surface: 2mm surface hoar.

Photos:

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Human-triggered avalanche in Paradise Divide

CB Avalanche CenterCBAC Observations

Date of Observation: 12/03/2021
Name: Ben Pritchett

Zone: Northwest Mountains
Route Description: Mt. Baldy, Paradise Bowl.

Observed avalanche activity: Yes
Avalanches: It looks like a skier triggered, and possibly took a ride in a small avalanche on the northwest-facing portion of Paradise Bowl. From the other side of the valley, it appears that someone post-holed out of the debris pile. There’s a stand-alone skin track going to the debris pile as well, indicating someone might have made a quick trip to the debris as well.

Photos:

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Florida of the Rockies

CB Avalanche CenterCBAC Observations

Date of Observation: 12/03/2021
Name: billy barr

Zone: Southeast Mountains
Route Description: Gothic

Observed avalanche activity: Yes
Avalanches: There was a slab release, looks like a 1 foot fracture that went nowhere, on the ESE facing end of Gothic Mountain a few days back but too small to get any photo of and only visible in the early morning sun.
Weather: In 4 of the past 5 days there has been a record high temperature, including beating the old record yesterday by a whopping 3½ºC. Everyday since November 28 has set a record for the shallowest snowpack for those dates and this will continue until we get a few inches of snow. Currently there is 1″ on the ground (with this little snow that amount is an average of the snow depth in a given area around the snow pole, though actually this is what is at the pole right now). Yesterday’s high was 55ºF and it has been at 50º or warmer the past 4 days and 47ºF or warmer for the past week. (note that these temperatures may seem too high but i have multiple temperature devices to make certain these numbers are accurate). This winter now has the least amount of snowfall to date of any winter of the past 48 years- not, however, the least amount of SWE given the high density of snowfall.

5044

Mapping weak layer distribution

CBACCBAC Observations

Date of Observation: 12/02/2021
Name: Zach Guy

Zone: Northwest Mountains
Route Description: With a weather pattern change expected next week, we traversed through the Ruby Range covering a lot of aspects and basins to map out the current snow surface, which could become a major persistent weak layer for the season.

Observed avalanche activity: Yes
Avalanches: A few very thin wind slabs on SE aspects of Oh-Be-Joyful Peak that might have run during Tuesday night’s increased winds, D1 in size.
Weather: Unbelievably warm. Light westerly winds.
Snowpack: See the sketch below which generalizes surface conditions. The biggest takeaway is that there will be significant differences in stability depending on aspect if next week’s storms deliver us a slab. The northern third of the compass is by far holding the weakest snow, both at the surface and throughout. It is especially weak in shallower areas, wind sheltered areas, and/or at lower elevations. I spent a lot of time looking at east aspects: there are some dramatic transitions in surface conditions that happen over only a small change in compass direction (see photo below). Over the span of ~20° or 30° near due east, the surface changes from dry to thin crust to a crust that is 6″ thick or so. In general, the snow on easterly aspects isn’t as weak as I’m used to seeing during dry spells of similar length in years past, due to the unusually warm temps. I didn’t travel much on westerly slopes, but expect similarities there. Southeast to southwest aspects have melt grains going deep into or throughout the entire pack where snow exists. The surface hoar from Sunday night’s event has been mostly destroyed by wind and sun.
These observations pertain strictly to slopes steep enough to avalanche; lower angled slopes have notable differences in surface characteristics and coverage. Furthermore, terrain features shaded by pine trees have colder, drier snowpacks than what I’ve generalized for open slopes.

Photos:

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Elk Basin

CB Avalanche CenterCBAC Observations

Date of Observation: 12/02/2021
Name: Eric Roberts

Zone: Northwest Mountains
Route Description: 11:00-15:45
Toured Elk Creek towards Scarp Ridgeline to assess snow instability and coverage before potential storm pulse moves in next week.
Descended same route with spring-like surface conditions back to Kebler Rd.
Sunny, warm day with no alarming results.

Observed avalanche activity: No
Avalanches:
Weather: CLR
Calm winds BTL-NTL, with light W wind near ridgeline 12,000’+.
36F @ 9,400’ (11:00)
42°F @ 11,850’ (13:30)
No Precipitation
No riming observed
Snowpack: Snow Surface: 2-12mm surface hoar feathers 9,800’-10,800 in sheltered terrain.
Roller balls present at 11:30 on Southerly aspects
Widespread moist surfaces with a 2-3cm thick MFcr above unsupportive wind stiffened snow and/or NSFs @ 11,000+ in non-shaded areas.

Ski/boot pen: 15cm/ 5-30cm

Overall, the snowpack is sporadic and terrain/aspect dependent, specifically NW-NE aspects harboring 10-65cm with an upside-down structure.
Test results showed poor structure, moderate, strength and low propagation propensity due to inconsistent slab layering and continuity.
Most wind sheltered areas do not have a slab component, mainly unsupportive and cohesionless facets making up the bulk of the pack. Areas where a slab recipe is found are wind-packed slopes, leeward slopes and ridge lines where assessing for overhead hazard could mitigate exposure.

Photos:

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