Location: Crested Butte Area
Date of Observation: 12/10/2018
Name: Crested Butte Ski Patrol

Subject: Post control release with ski cut
Aspect: East
Elevation: 11400

Avalanches:

ASu-R1-D.5-O.

Explosives had been thrown in the area nearby, on more southerly aspects affecting only new storm snow or wind slabs. The area subsequently ski cut had not been previously affected by traffic or explosives, and contained unique terrain features, acting as trigger points, that were linked by the ski cut. The resulting failure was not anticipated. No other results from ski cuts were observed on similar aspects or elevations.

Weather: Clear, mid-20’s, calm
Snowpack: Typically supportive mid pack, new snow & recent wind slabs reactive to explosives at depths of 6″-8″ were observed. Depth of snow at ski cut that triggered release was approximately 55-60cm. 6-8mm surface hoar observed near and above tree line on east through north facing aspects.

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Location: Crested Butte Area
Date of Observation: 12/09/2018
Name: Tom

Subject: CBSPSP Hall of fame
Aspect: North
Elevation: 11800

Avalanches:

First avalauncher round of the season. The first shot propagated aprx. 400′ . #2/3 no results. #4 propagated rapidly (shattered glass)
#1 AL-R2-D2.5-G
#4AL-R1-D2-G

Weather: Clear skis light winds NTL and Mod winds ATL from the NNW. Wind was transporting snow off the peak of Mt. CB throughout the day. 1-2 mm surface facets formed from the night before on N-W aspects own the ski hill.
Snowpack: Wind loading ATL forming specific terrain feature with wind slabs. On N aspects snow pack is continuing to weaken and facet.

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Location: Kebler Pass Area
Date of Observation: 12/09/2018
Name: Cam

Subject: Snowpack still adjusting
Aspect: North, North East, South, South West
Elevation: 9-12.5 K

Avalanches:

One seemingly large avalanche on Axtel in 4th Bowl. Didn’t have a good enough view to notice any details. Clouds made it hard to see anything all day.

Weather: Light snowfall in the early AM. Felt humid. Winds generally calm except for above treeline. We didn’t see a lot of transport happening on the southern end of the forecast zone. Clouds came and went (mostly hung around) all day.
Snowpack: While skinning up a shady N aspect experienced numerous collapses between 10,000 ft. and 11,000 ft. Hand pit showed 65cm HS. Fairly consistent 4F all the way down to depth hoar on the ground. Collapsing stopped once the HS got deeper as we climbed, closer to 100-110 cms near and above treeline. Same structure existed, but no longer showed reaction to our weight.

Same exact thing happened on a different peak later in the day, but collapsing occurred both in and out of the trees.

South and Southwest aspects were more thin with no obvious signs of instability and a crust forming on the surface.

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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.

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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

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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:

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:

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.

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