CBAC Snodgrass Study Plot Snowpit

Location: Crested Butte Area
Date of Observation: 12/08/2016
Name: Arden Feldman
Subject: CBAC Snodgrass Study Plot Snowpit
Aspect: North East
Elevation: 9760

Avalanches: None
Weather: See Profile
Snowpack: See Profile

December-8-Snodgrass-Pit

Mt. Emmons

Location: Kebler Pass Area
Date of Observation: 03/26/2016
Name: Seth Beers
Subject: Mt. Emmons
Aspect: South East
Elevation: 12250′

Avalanches: Old crown – likely from mid-week storm on bowl just to lookers right of Green Lake on Mt. Axtell – R2.5, D2
Weather: Cloudy with periods of clear sky. Light winds from both SW and NW with blowing snow at ridge lines.
Snowpack: See Avanet pit profile attached. HST varied fro 5 cm to 20 cm throughout tour depending on elevation and exposure to wind transport with MFCR sandwich in the top portion of the snowpack. HST was unconsolidated and temps seemed to stay cool today to prevent moisture buildup on SE aspect – maybe down to ~10K’. Descended at ~330 pm.

Did see a repeated CTH results just below the DH layer below an ice layer but think this was due to isolating the column in the test. During my tour and I never punched blow the early March MFCR that sits below the recent storm layers.

03.26.16-obs

Whetstone

Location: Crested Butte Area
Date of Observation: 03/10/2016
Name: Zach Guy
Subject: Whetstone
Aspect: North East, East, South East, South
Elevation: 8,800 – 12,100

Avalanches: None in this area. Observed a handful of fresh wet loose today further up valley in areas that had more snow from the last storm (Mineral Pt, Mt. CB, White Mtn, etc) on SE, S, SW, and W aspects N/ATL, all D1 to D1.5 in size.
Weather: Warm temps. Measured 34*F at 12,100 ft at 14:30. Calm to light breeze from the west. A few thin clouds.
Snowpack: See video. 2-4″ of settled storm snow was not enough to cause any real concerns for wet loose or our new layer of persistent slabs over the 3/6 facets in this area. On SE and S facing slopes, the recent storm snow became wet and consolidated to less than an inch thick above the still frozen 3/6 crust/dust layer without any rollerballs. On the most windloaded ATL slopes facing NE, there was 8″ of F+ settled snow over the 3/6 facet layer, and we did not see signs of instability or get any results on this layer in a pit. I probed around on several E and NE facing slopes above treeline and found a widely variable structure, generally shallow. Profile from a somewhat representative location below.

3/10. Snow profile on NE aspect ATL of Whetstone Mtn

3/10. Snow profile on NE aspect ATL of Whetstone Mtn

DSCN0684

Natural wet loose off of S face of Mineral Point

Snodgrass // California Bowl

Location: Crested Butte Area
Date of Observation: 03/06/2016
Name: Seth Beers
Subject: Snodgrass // California Bowl
Aspect: North East
Elevation: 11,000′

Avalanches: No new avalanches observed. Old crowns from early Feb storm can still be seen.
Weather: @ ~11:00 am, overcast, calm winds, light snow (S1 – S2)
Snowpack: See attached test profile from NE aspect on Snodgrass. HS of 160 cm with a fairly well-developed layer of near surface facets in the top ~5 – 10 cms that sat above a cohesive slab of various firmness down to 45cm. Large F firmness DH from here to ground. Managed a CTH result on the slab / DH interface @ 45cm.

Highly variable snowpack on the way down on similar aspect ranging from the snowpack described above, to fully-faceted, to sun crusts, to bed surfaces from early Feb avy cycle. Facet sloughs were easy to initiate on steeper slopes but ran fairly slow. Near surface facets layer would seem to be one to keep an eye on during the next storm.

030616-Snodgrass-Profile

CBAC Snodgrass Study Plot Snowpit

Location: Crested Butte Area
Date of Observation: 03/05/2016
Name: Jimmy Buchanan
Subject: CBAC Snodgrass Study Plot Snowpit
Aspect: North East
Elevation: 9,750′

Avalanches: None.
Weather: See profile.
Snowpack: See profile.

March-5-Snodgrass

Friends Hut snow obs

Location: Brush Creek Area
Date of Observation: 02/22/2016
Name: Zach Guy
Subject: Friends Hut snow obs
Aspect: South East, South, North West
Elevation: 9,000-11,400 ft

Avalanches: No recent avalanches or signs of instability en route to Friends Hut. It looked like only 2 of the big SE/E facing paths above Brush Creek on Timbered Hill ran naturally during 2/1 cycle, D2 in size. Never got good views of the alpine above Friends Hut.
Weather: 2/21. Warm, few clouds.
2/22. Overcast skies cleared to scattered. S-1 to S1 in the a.m., with less than an inch of accumulation. Moderate NW winds with moderate transport at times.
Snowpack: (See video). HS at Friends Hut is ~150cm. On the approach on Sunday afternoon, steep southerly BTL slopes were completely saturated and unsupportive (or melted out to dirt), but appear to have matured beyond wet loose or wet slab concerns. Overhanging slopes above Death Pass had minimal and patchy snow coverage. Dust event reached out to Upper East Brush as well, but not as bad as near town. Snow profile on a low angle, sheltered, northwest aspect near treeline showed a stubborn PS structure, with propagating test results after additional loading steps beyond standard ECT. See profile. I would expect starting zones on similar aspects to hold a widely varying structure due to our previous avalanche cycles and/or wind events.

NW aspect NTL

NW aspect NTL

Snow profile. NW aspect NTL near Friends Hut

Snow profile. NW aspect NTL near Friends Hut

Snodgrass snow profile

Location: Crested Butte Area
Date of Observation: 02/19/2016
Name: Level 2 Course
Subject: Snodgrass snow profile
Aspect: North East
Elevation: Below treeline

Avalanches:
Weather:
Snowpack: See profile

 

 

CBAC Snodgrass Study Plot Snowpit

Location: Crested Butte Area
Date of Observation: 02/17/2016
Name: Jimmy Buchanan
Subject: CBAC Snodgrass Study Plot Snowpit
Aspect: North East
Elevation: 9800′

Avalanches: None
Weather: See profile.
Snowpack: See profile.

Snodgrass-Feb.-17

Gothic obs from 2/12-2/14

Location: Crested Butte Area
Date of Observation: 02/14/2016
Name: Geoff Unger & Chris Pruden
Subject: Gothic obs from 2/12-2/14
Aspect: All aspects
Elevation: 9400-11000

Avalanches:
Weather: High pressure with lots of solar on Friday. Cloud cover moved in midday Saturday and it snowed lightly on Sunday. Light increased to Moderate winds as the little disturbance arrived on Sunday.
Snowpack: On Friday 2/12 we toured in the road and did beacon drills. Of note was how slight changes in aspect changed the character of the snow dramatically. All but the most sheltered terrain has developed a crust. Just touring up the road it is easy to see the widespread natural activity that happened as a result of the 2/2 Storm event with slabs running up to D2-D2.5 over the past 10 days

Saturday 2/13 We toured up Copper Creek to get snow profile information. We dug on a WEST aspect and had mixed column test results. Even on a relatively sheltered West the crest had formed to make skiing less than desirable. Link to snow profile below.

Sunday 2/14 We toured up to the Snodgrass-Gothic Saddle. There was still good snow available for skiing on NE, but as soon as we trended E even the slightest bit the dreaded crust appeared.

Compression Tests revealed Buried Surface Hoar down approx. 39 cm on hard results on a NE aspect
CT 26 SP down 37 V 2-3mm / .5-1mm
CT 16 SC down 39 V 2-3mm / .5-1mm
It is possible the first result was also a collapse, but had the appearance of a planar fracture where the second result was a clear drop of the column.

 

 

Cracking/collapsing on Whetstone

Location: Crested Butte Area
Date of Observation: 02/07/2016
Name: Zach Guy
Subject: Cracking/collapsing on Whetstone
Aspect: North East
Elevation: 10,000-11,000 ft

Avalanches: Most obvious paths ran naturally in this terrain on 2/1. D1.5 to D2’s in size. Took a quick look at one crown; ~2 ft thick over F+ 2-3mm facets. These paths also ran in December. Unfortunately, the bedsurfaces are crusty and there is 3-6″ inches of faceting snow above them already, ripe for 3x repeat offender if we get another big storm.
Weather: Light winds below treeline. Continued snow transport observed over Anthracite Range and West Elk Range, but minimal transport looking towards Pearl Pass, Brush, Cement, etc. Few clouds.
Snowpack: See video. On shaded low angle terrain below treeline, the snowpack was 50cm of slab (F to 4F+) over 50 cm of facets (Jan 14 interface, F+, 1-2mm). We crossed about 10 open meadows, and got 2 rumbling collapses. One as we regrouped and were stepping out of skis, the other by jumping on the snowpack on skis. The Jan 29th surface hoar layer (2-4mm, F) is also preserved about 30-35 cm deep, and propagated in 2 out of 3 of our extended column tests. (ECTPM, SC, Q1). We got several shooting cracks up to 20 feet long on this layer on small rollovers.

IMG_5748-002
IMG_5746-002
Profile NE aspect BTL

Profile NE aspect BTL