Skiing and hole digging

CB Avalanche Center2018-19 Observations

Location: Paradise Divide Area
Date of Observation: 12/09/2018
Name: Eric Murrow

Subject: Skiing and hole digging
Aspect: North East, South West, West
Elevation: 11,000′ to 12,400′

Avalanches:

One very small, thin wind slab in east bowl on Baldy immediately below ridgetop.

Weather: Filtering low and midlevel clouds and sunshine. Winds near and above treeline were light with occasional drifting off the tallest and most exposed peaks and ridges. Air temps were cool, but solar radiation was strong enough to moisten slopes near 30 degrees or steeper that faced very close to south.
Snowpack: While traveling across steeper southerly slopes the snow surface became moist by midday even above treeline up to 12,400′.

Dug a profile on a northeasterly (51*) slope near tree line at 11,700′, HS 97cm, slope angle 24 degrees. Test results most notably showed CT 11SC on Thanksgiving interface, 2-3mm facets, ECTP 19 and ECTP20 on same facets. See photo below.

Photos:

Managing West for PSa

CB Avalanche Center2018-19 Observations

Location: Paradise Divide Area
Date of Observation: 12/09/2018
Name: Evan Ross

Subject: Managing West for PSa
Aspect: West
Elevation: 10,500-12,000

Avalanches:

Saw a small windslab run naturally in the afternoon at an ATL elevation, on a southerly slope above the 401 trail.

Weather: Mostly clear and generally light northwest winds. At ridgeline moderate gusts where just enough to drift snow. Drifting snow was happening mostly above the elevations we traveled.
Snowpack: Recreational pow day. Bottom line, traveled on westerly slopes with the same Persistent Slab terrain management that I would use on say, a northerly slope. You could easily feel the PS structure with your pole. We didn’t investigate further and managed our exposure for that problem. Skied to 35 degrees with no obvious signs to instability. Skied steeper slope angles on slopes that had previously avalanched this winter and had lost the PS structure. HS ranged from 80-100cm

Photos:

Snodgrass Tour

CB Avalanche Center2018-19 Observations

Location: Crested Butte Area
Date of Observation: 12/09/2018
Name: Avy 1 course

Subject: Snodgrass Tour
Aspect: North East
Elevation: 10,301

Avalanches:

Wet Loose on Gothic bottom of the spoon and looker right S/SE aspects
Wind Slab off peak of Gothic N/NE
Avery large dry loose S/SE aspect
multiple loose stuffs on red lady bowl

Weather: Temp: low 20’s
Sky: Clear
Wind: Light out of the NW
Precip: None
Snowpack: Pits
Aspect: NE
Elevation 10,301
HS: 84-72cm
Basel facets ranged 13cm-22cm

Tests :
CT11 SP & CT12 SC

Lots of cracks and collapses throughout our tour.

Photos:

Upper Slate River tour

CB Avalanche Center2018-19 Observations

Location: Paradise Divide Area
Date of Observation: 12/08/2018
Name: Eric Murrow

Subject: Upper Slate River tour
Aspect: North East, East, South East
Elevation: 9,500′ – 11,600′

Avalanches: Spotted several new slides, a D1 east facing slab near Wolverine Basin, D1 slab NE low down on Schuylkill Ridge(reported in early ob from today title Slate obs by Joey), several D1 loose(likely wet) on south slopes below Paradise Divide proper below treeline, and another D1 on on east aspect of Cinnamon (hard to tell if loose or small slab because of oblique viewing angle.

Weather: Skies were partly cloudy with mid and low-level clouds moving in and out during the day. Light snowfall on and off as well but no real accumulation. Winds below treeline were calm to light with little to no gusting. Ridge top winds, at treeline, picked up a bit with visible efficient transport of snow just up the ridge from us.

Snowpack: While ascending generally east facing terrain, we did not experience any collapsing. Below treeline HS ranged from 70 to 100cm. Dug quick hole on east aspect, 30* slope, 10,200′ found HS 100cm. Basal 10cm were moist facets (moist enough to make quality snowballs out of 2mm facets) that were showing signs of early rounding process. The overlying slab was pencil hard at the bottom but was mostly 1finger and quickly transitioned to 4finger and fist at the surface. CTH results on basal facets, and CTM, Q2 result at interface atop Thanksgiving slab. In adjacent area poked a quick hole on NE aspect and found facets at the ground to be dry.

As we approached treeline, depth became a bit more variable from the wind, but HS bumped up to around 70 to 125cm on the skin track. On final portion of skin track, we were nipping at the shallow edges of deeper, drifted near treeline slopes in excess of 30* without any results.

Got a reasonable window of visibility at ridge top, take away was many westerly slopes above treeline still have available snow for transport, ex. west side Purple Ridge, westerly bowls of Baldy, and west side of Gothic.

Photos:

Red Lady Glades

CB Avalanche Center2018-19 Observations

Location: Kebler Pass Area
Date of Observation: 12/08/2018
Name: James Bivens

Subject: Red Lady Glades
Aspect: South, South West
Elevation: 11,500

Avalanches:

We observed a R1, D1 slide on the saddle in-between the summit of Red Lady and Coon Basin on a steep south aspect.

Weather: Partly cloudy with the occasional snowflake.
Snowpack: One meter deep near tree line on a south facing aspect. A column test fractured the layer (about 5 inches down) between recent snow and the older, more consolidated layer on the seventh tap from the elbow. Nothing in the column fractured after that. There was a hard, defined icy layer in-between the ground facets and the bottom most consolidated layer of snow. Lower below treeline the new snow had turned into a, challenging to ski, breaker-crust. Our party of four observed no collapses or shooting cracks, and we kept our slope angle under 30 degrees.

Photos:

snodgrass front side obs

CB Avalanche Center2018-19 Observations

Location: Crested Butte Area
Date of Observation: 12/08/2018
Name: Irwin Guides

Subject: snodgrass front side obs
Aspect: North East
Elevation: 10300

Avalanches:

none seen

Weather: mostly clear, occasional overcast
Snowpack: Hs 60 cm
6-10 cm of basal facets
1 finger consolidated mid pack with fist hard 10-15 cm surface snow.
lots of collapses in open meadows, shooting cracks. didn’t go anywhere.
CT 11, Ect 11 on NE aspect 10,300 elevation.
-2c air temp

Photos:

Slate Obs

CB Avalanche Center2018-19 Observations

Location: Kebler Pass Area
Date of Observation: 12/08/2018
Name: Joey Carpenter

Subject: Slate Obs
Aspect: South, South West, West
Elevation: 9600-116000

Avalanches:

E face of Richmond 12.2k. SS-N-R1-D2, probably ran yesterday. Observed from very far away.

Numerous point releases on solar aspects in steep terrain.

NE aspect below Schuykill ridge 10k. SS-N-R1-D1, likely from yesterday.

Weather: Varied between FEW and SCT clouds throughout the day with brief periods of S-1 snowfall midday. 5-10mph winds out of the W/NW created light snow transport on W facing aspects ATL, if they weren’t already scoured.
Snowpack: 45cm average HS WSW aspect ~10k held melt freeze crust with small facets below from early Nov snow. Thanksgiving storm and snow from last ~10 days is uniform (4F) .

100cm avg HS SW aspect 11k. Three moderate sized collapses in flat, sheltered terrain all within ~20 minutes of each other.

Photos:

Coney’s (Late AM/Early PM)

CB Avalanche Center2018-19 Observations

Location: Crested Butte Area
Date of Observation: 12/08/2018
Name: ADB

Subject: Coney’s (Late AM/Early PM)
Aspect: East
Elevation: BTL

Avalanches:

Unlike two weeks ago, no whumping, cracking, or collapsing on and off the skin track.

Weather: Broken skies, calm in the trees with light wind from the west on the open ridge. No snow transport. There was a 5 minute burst of S-1 snowfall in the afternoon with no snow accumulation.
Snowpack: Snowpit:
35 Degree slope 50 feet below the ridgeline:
depth: 105 cm of snow.
Did 2 compression tests and both came out CTN.
about 10 cm of facets at the very bottom.

Photos:

Pittsburgh Thursday and Friday

CB Avalanche Center2018-19 Observations

Location: Paradise Divide Area
Date of Observation: 12/07/2018
Name: MR

Subject: Pittsburgh Thursday and Friday
Aspect: North East
Elevation: 9,500-10,500

Avalanches:
Weather:
Snowpack: Thursday – hoar Frost on skintrack. No signs of instability.
Friday – skiing same terrain as Thursday, got 3 whoomphing collapses

Photos:

Variable Sensitivity

CB Avalanche Center2018-19 Observations

Location: Crested Butte Area
Date of Observation: 12/07/2018
Name: Evan Ross, Zach Kinler

Subject: Variable Sensitivity
Aspect: North East, West
Elevation: 9,800-11,000. BTL

Avalanches:

SS-AS-R1-D1.5-O BTL West Facing Aspect. Crown about 60cm with only about 5-10cm of 4f slab in there. Failed on large facets on the ground.

D2.5? Very large avalanche off an Above Treeline easterly aspect of Gothic mountain. Could only see parts of the crown and never saw the debris. Probably ran within the last 24hr.

SS-N-R1-D2 ATL on the southerly face of Mt Bellview. Looked like it ran in the upper snowpack as a windslab. Probably ran within the last 24hr.

Belleview Mountain South: SS-N-R2-D2-I (this is a different mountain than the one above.)

SS-N-R1-D2 ATL on an easterly aspect of Baldy Mountain. . Probably ran within the last 24hr.

Numerous small loose snow avalanches that ran today on upper elevation steep and rocky southerly faces.

Weather: Fog in the upper Crusted Butte Valley in the morning and moving out around midday. Otherwise few clouds. Calm winds. Good solar.
Snowpack: Variable sensitivity to the PS avalanche problem. On BTL north east, we got some good collapsing and shooting cracks up to 15ft on slopes in the lower 30 degree range. The couple of steeper slopes over 35 degrees we visited had previously avalanche this winter. The slopes that avalanched earlier in the winter had refilled and were tough to distinguish between those that hadn’t avalanched. In a profile on one slope that had previously avalanche, the HS was about 20cm’s less, lacked a slab, but maintained about 5-10cm of large grained facets on the ground. So difficult to tell which slopes or where on a slope the PS structure was present and currently reactive.

On a westerly aspect BTL and protected from the wind, the snowpack structure mirrored that of a NE aspect. Otherwise, the more open westerly aspects appeared thin and sharky.

Photos: