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

Subject: Swiss cheese
Aspect: North, North East
Elevation: ATL, BTL

Avalanches:

None seen but it was milk jug in the valley

Weather: windy and snowy on the ridge and at treeline, calm and snowing lightly below treeline
Snowpack: Looking at the ridge from down valley, you could see it had been wind scoured on the south side. Denser wind effect on top of a snowpack that was 140 cm deep at treeline. Below treeline snowpack was light on top, denser in the middle and sitting on crap at the bottom. Appeared to be a buried surface hoar as well 10 or so cms down. Classic strong over weak structure. The swiss cheese comment comes from an old mentor of mine who pointed out that while the pack may look and feel good in a lot of spots, there are still holes in random areas and to always be aware. Thin crust on anything facing E/SE. Bottom part of pitch to the valley floor was still unconsolidated top to bottom in the pack and about 40 cms deep.

Photos:

Eleven Snowcat Terrain 12/11/18:

Notable collapses on South facing terrain,  Multiple ECTM results with Sudden Collapse failures indicating the potential for propagation. Snow profile on South had failures below a crust capping early season facets, while on West there was no crust but failure on same early season facets.

Location: Paradise Divide Area
Date of Observation: 12/11/2018
Name: Eric Murrow

Subject: Below treeline northerly slopes
Aspect: North, North East
Elevation: 9,500′ to 10,600′

Avalanches:

Spotted a fresh windslab on easterly aspects in Baldy south bowl, had a very tangent view of it, ran a couple hundred vertical, D1 in size.

Weather: Just under an inch of new snow this morning. Winds were pretty quiet at our below treeline location. Clouds decreased throughout the day.
Snowpack: HS throughout this tour ranged from 70 to 135cm. 70 to 90cm was about average for sheltered locations. Dug in two locations, one drifted 135cm and another more average HS of 80. The first location was 10,600, NNE(10*), 29* slope, HS135. The structure showed fist density surface quickly transition into 4finger and then 1finger+ density slab resting over 2 to 3mm advanced facets that were showing signs of rounding. Test results at this location were ECTP21 and PST 40/110 end on the oldest facets on ground.
The second location was at 10,000′, NE(45*), 34* slope, HS80. The slab in this location was weaker at 1f- hardness and obviously much thinner. Test result was ECTN23 on facets resting on ground. The faceted grains at the ground were showing signs of rounding.

Photos:

12/11 Fresh windslab on east aspect of Baldy south bowl

Location: Crested Butte Area
Date of Observation: 12/11/2018
Name: TC

Subject: Schuylkill Ridge
Aspect: North East
Elevation: 9,200-11,400

Avalanches:

No new avalanches observed. Several small pockets in the upper half of the re-skin forest had slid (10-12 inch crowns) in the last couple of weeks.

Weather: Overcast and very light snow first thing in the morning; clearing to mostly sunny by mid-day. Calm winds with temps in the upper teens to lower 20s.
Snowpack: Overall, the snowpack seemed to be right side up. Pole probing as we ascended the lower benches below Snake in the Grass, revealed unconsolidated (on the verge of faceted) snow on top of a more firm base. Continuing our ascent, measured an HS of 85 cm mid-way up Runaway Ski. At the top of the re-skin, dug a profile pit at the entrance to Runaway (in the low saddle) and found an HS of 115 cm. The top 20 cm was fist hard new snow from the past couple of weeks; the middle 50 cm was a three-finger hard layer presumably from the Thanksgiving storm; the bottom 45 cm was 1-2 mm facets (to the ground). Only experienced one small collapse throughout the entire tour. Skied Yogis and the northern ridge of Thanksgiving Bowl, and the snowpack felt quite stable.

Photos:

Location: Paradise Divide Area
Date of Observation: 12/10/2018
Name: Eric Murrow

Subject: Daisy Creek area
Aspect: South East, South, South West, North West
Elevation: 9,600′ – 11,700′

Avalanches:

Lots of small wet activity in the area on sunny BTL slopes for previous days. No new slabs visible.

Weather: Beautiful day – cold in valley bottoms but significantly warmer on the ascent. Lots of sunshine and calm winds with an occasional light breeze.

Snowpack: Snow surfaces on SE,S, and SW became moist by 10am BTL and slightly moist on S around 1230 at treeline.

Poked two quick holes – first was below treeline at @ 10,850′ HS 123 (slightly drifted site, generally around 100cm) 11/22 interface was crust with Thanksgiving slab resting on top. Most notably was two melt-freeze crusts, one at the surface and another thin crust in top 20cms. ECTN at this location. The surface was a moist crust. Not much concern at the moment with this structure.

The second hole was on a south-facing slope at 11,700′, HS on this slope was a little more than a meter in general. Probing on ascent revealed weak faceted grains below Thanksgiving slab. Hasty pit structure looked poor for a south facing slope with 80cm slab resting on 2mm facets from early November snow. Probed on the descent and confirmed structure for the length of the 500′ vertical slope.

Photos:

Location: Paradise Divide Area
Date of Observation: 12/10/2018
Name: MR

Subject: Upper Slate
Aspect: North East, East, South East
Elevation: 9,500-11,500

Avalanches:

large avalanche on east face of Richmond and smaller one off angel pass, see photo.

Weather:
Snowpack: at 11,000 east facing, height of snow about 100cm. No instabilities observed, didn’t ski steeper than 30 degrees or so tho. Snow had gone thermal on any aspects that were at all southern tipped.

Photos:

Both slides already observed earlier in week (forecaster note)

Location: Crested Butte Area
Date of Observation: 12/10/2018
Name: Tom Schaefer

Subject: SE face White Rock
Aspect: South East
Elevation: 13,200′

Avalanches:

SE face White Rock Mt. observed from CBSP top shack.
N-R3-D3-O
This was observed from a great distance so the relative/destructive size is approx.. at this time.

Weather: Clear skies winds 17-26 mph out of the WNW from the Cinnamon Wx station. temps in the mid 20’s at that elevation.
Snowpack: N/O

Photos:

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.

Photos:

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.

Photos:

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.

Photos: