Name: Travis Colbert
Title: Lower Wolverine Basin
Location: Crested Butte Area
Date of Observation: 01/06/2015
Aspect: North West
Elevation: 10,600

Avalanches:

Weather: Warm (30 degrees), low cloud layer in the Slate River valley, clear blue skies above. Calm winds.

Snowpack: Test pit on a 38 degree rocky rollover. 110 cm total snow depth. 52 cm of fist to four finger soft snow on top of “December 13th interface” of 1-2 mm facets. 20-30 cm of two and three finger hardness below December 13th interface sitting on 10 cm of 2-3 mm facets at the ground. Conducted several shovel compression test with widely mixed results from CT7 with a sudden collapse on the December 13th interface to CT30 that shovel sheared at the ground. One of the columns failed when cutting on the December 13th interface. Rock outcroppings in the vicinity of the test pit seemed to be contributing to the widely varied results. Bottom line, while much of the snowpack might be “MODERATE”, there seems to be plenty of sensitive pockets that can be easily triggered by the weight of a skier.

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Name: Evan Ross
Date: 1/16/15
Location: Snodgrass Road
Aspect: NE

Weather: Low clouds and overcast this morning. Burning off by 11am to few clouds. Much warmer then that past week.

Snowpack/Avalanche Obs: Passing by NE side of snodgrass on the Gothic road.  Certainly a widespread Persistent Slab cycle on the mid and upper slopes of Snodgrass. Classic avalanche terrain generally over 34 degrees was a main characteristic. Lots of wind effect in the east river valley. Looked like more wind stripping then wind loading, but obviously there were some cross loaded pockets too. Lots of loosing snow avalanching on sunny slopes but all d1-d1.5.

Guides(s): Jeff
Date: 20150104
Level One Avy Course, Tour Day
Location: East River Valley/Gothic
Elevation: 9400′ – 10,000
Aspect: SW-N-ENE

Weather: Variable/Overcast, flat light, dry most of the day, a few flurries. Winds light to strong, mostly N channeled down valley.

Snowpack/Avalanche Obs: Approximately 12 recent avalanches along Snodgrass seen from the Gothic road.  Looked like skier triggered within the PWL.  ~5 D1.5’s (small but going into gulley terrain traps where the debris piled up deeply) ~7 X D2’s.  At the far end of Gothic Mtn (across the bridge) we remotely triggered a D1.5 from ~50m away on a 25* slope.  the whole slope cracked & the pocket went within the PWL of very large facets.  looked like 33-35* slope angle from 50m.

Overall, snowpack is shallow & week 50-100cm.

We got collapses & shooting cracks on a SW (240*) slope BTL @15* (guessing the crust wasn’t strong enough in a semi shaded low < slope).

Ditto on W, E, ENE  (Pit collapsed before we dug it on the approach!)

Probably 10 collapses in all spanning large distances.

ENE pit: The structure is >5mm Facets w/ soft (often 4F slab over the top).

WSW pit: (10 m away from above pit) 25* slope, knife hard 6cm crust over facets with perc. columns in the facets showed no propagation and only Q2/Q3 failures within the top layers resting on crust.

Guide(s): JSJ
Date: 20150105
Activity: BC Ski
Location: Snodgrass
Elevation:9400′ – 10,000
Aspect: E/SE

Weather: Broken to scattered clouds. 3cm new snow. Moderate and sustained winds from West and North (down valley funnel) most of day.

Snowpack/Avalanche Obs: Same as previous post from yesterday in same zone. Got a few collapses and shooting cracks on 25 degree slopes on an East aspect. Ski pen at times was full depth. Downvalley N winds were transporting new low density snow and re-filling the skin track between laps.

Recent Observations: (Surface, structure, cracking, collapsing, PWLs, Ski Pen)

Wind stripped snow in higher terrain exposing old tracks on west terrain even in mid to lower westwall. Looked like straight west Winds. Small isolated wind slabs up to 1F hardness. Snow remained dry, no solar radiation.

East: Paperboy Route w/ ski cuts, no explosives. Fresh Wind slabs developed very touchy with ski cut triggering wind slab in Swill & Bender. Swill SS-ASc-R1-D1-I. 100’ wide 10-20” deep, ran 500’ through choke. Candy’s & Sonic also triggered but smaller 6” deep, ran short of Choke. Wind slab less developed past pre-evac.

South: Small 4” windslabs in Sunny Shoulder barely running. Cocktail Bowl Skiing very well!

West: Sunset L&R a little wind effected but good, small windslab from a ski cut on round two. 8-12” deep 30’ wide, ran 40’.

Upper Upper: Isolated windslabs in lower UUWW. Not UUWW proper. Very shallow windslabs 1F pulling out and stubbornly running short distances from airblasts. Significant scouring, probably lost 1-3f feet of snow depth from terrain. Probably one reason for no results, decreasing load!

Name: Zach Guy/Evan Ross
Title: Schuykill Ridge
Location: Paradise Divide Area
Date of Observation: 01/05/2015
Aspect: North East
Elevation: 9,100-11,300

Weather: Broken skies becoming scattered to few  in the late afternoon. Moderate to strong W/SW winds at ridgelines blowing snow. In valley bottoms light to moderate winds were also drifting snow.

Snowpack: Toured in the Schuykill area observing the persistent slab structure through different elevation bands:

Below 9,600ft
Persistent slab structure was very weak with a faceting slab. A few collapses but no shooting cracks. ECT results were non-propagating slab fractures (ECTN, moderate to hard). Areas with previously wind hardened snow were most suspect.

9,600ft to 10,000ft
The slab gained enough strength or cohesion (F+ to 4F, 60 cm thick) to produce a shooting crack on a 33 degree slope after a collapse.

10,000-11,300
Persistent Slabs became quite with no collapsing. HS averaged 100-140cm, slabs about 70+ cm thick. The 12/13 interface was obvious in the snowpit wall and still very weak facets, but ECT tests did not produce any results (ECTX), Compression tests produced sudden collapse results on the 12/13 facets.

Avalanches: Shallow windslabs were touchy at ridgeline on Northeast aspects near treeline. Two skier triggered windslabs generally 2-4″ deep but up to 6″ in places. 30-40ft wide and one ran 500 vertical feet but was still a D1. We watched a natural avalanche mid day on  a NE aspect near treeline. Appeared to be a shallow windslab that then stepped down to a 100 ft wide persistent slab, maybe a foot or two deep, but we observed this from valley bottom.  The whole mess ran 1,000 vertical feet and was large enough to bury a person.  SS-N-R1-D1.5-O.  That slope had slid previously on the Dec 13th facets in mid-December.   Lots of evidence of widespread avalanches during the meat of the avalanche cycle back in late December.

Name: Dustin
Title: Poverty Gulch 1-5-15
Location: Paradise Divide Area
Date of Observation: 01/05/2015
Aspect: North, East
Elevation: 9500-10500

Avalanches: Triggered multiple wind slabs (all D1) while riding and one snowmobiling. The first was triggered on a small cross-loaded convexity on the bench. It was only 2-3 inches deep, seemed to be windblown snow from today. The slab didn’t have enough weight to run more than a few feet downhill, but for how small it was it propagated around 10ft. Our party triggered another, seemingly identical slide on a similar slope lower down. The third was triggered below a leeward ridge and was a little bigger (3-5 inches and 15 ft) but also didn’t run on the relatively shallow slope (25-30 degrees). The final slide was triggered on a small E-aspect on the valley floor that received tremendous wind loading. The slide was triggered from a convexity/windlip and was between 5-15 inches deep across the crown. The slide ran on a Q1 surface, beautifully planar but I couldn’t identify the weak layer between that and the stiff wind slab that was the bed surface. Sun crust or surface hoar? All R1-D1- AS-SS except the snowmobile trigger.

Weather: Windy! Clouds were in and out throughout the day but never had full sky coverage. Strong winds from the West and Northwest that were heavily loading slopes frequently throughout the day. Pretty warm besides the wind.

Snowpack: Less supportive in lower elevations and less wind affected areas. More snow up high. Dug on a small test slope on the bench below the N-face of Schuylkill false summit, seemed to receive a good bit of wind loading. Was more than 5 ft and didn,t touch the ground. Around 1-2 ft of softer snow (f and 4f) on top of a stiffer slab (1f). I imagine that this is the slab from the Dec. 22nd storm. Underneath the Dec. 22 slab was softer faceted snow, but seemed somewhat cohesive as well.

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Name: Ben Pritchett
Location: Snodgrass
Date of Observation: 01/05/2015

Snowpack: No questions about the distribution of the Dec 13th weak layer. It’s widespread and continuous in the Crested Butte zone in the near and below treeline areas. The uncertainty with the Persistent slab problem is with distribution of the slabs themselves. Based on observations over several days around the Slate and Washington Gulch areas, seems like the collapsing happens pretty consistently (several to many a day) in undisturbed areas where there is more than 45-50cm of recent snow on the Dec 13 interface. If there is less than 40cm over the Dec 13 layer, seems like the skiing gets punchy and you’re penetrating through the slab skiing in the weak layer, surfing facets. Bottom line, in the shallower snowpack zone around town, ski pen is a pretty handy observation at the moment to track the presence or absence of the persistent slab problem across terrain features; if ski penetration is less than about 20cm, it’s likely that you’re riding on top of a slab that’s perched on a guilty weak layer. Right now, contrary to the common strategy of avoiding weak areas, it worked well to stick to the shallower weaker snow and surf the facets. I’m inclined to avoid skiing steeper slopes below treeline that feel supportive.

3 collapses, each in open areas where slab was supportive (ski pen

Location: Kebler Pass Area
Date of Observation: 01/04/2015
Aspect: North
Elevation: below treeline

Avalanches: I traversed the small, shallow, cross loaded slope toward dense trees. The slope collapsed and propagated ten feet above me and ~100 ft wide. The angle was low 30’s so it was very slow moving and I had no problem getting to the trees. The crown was about 2ft and composed entirely of dense wind slab. the top ~30ft ran on the ground and some debris slid~300ft, stopping at the trees. We also noticed an east facing slide up moonscape. It appeared to be natural, wind slab under a cornice, maybe ~50 ft wide R1 D1

Weather: cloudy, west winds ~20mph

Snowpack: We saw an old crown that seemed to propagate across the skiers right half of Axtel’s 2nd bowl. It was pretty filled in. There was not a place near the start zone that we felt comfortable digging a pit. We decided to ski corner pocket of first bowl. Lower in first bowl, the snow became more wind affected. We took the gully right, crossing scoured snow. At a high point of lower angle terrain between the exits of 1st and 2nd bowl, the slope was heavily cross loaded.

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Name: Peter Richmond
Location: Crested Butte Area
Date of Observation: 01/03/2015
Aspect: North East
Elevation: 10, 600

Avalanches: Yes, one large slide, after ski cut, skier traversed out of slide, the area was in the glades at the very top of slope that progressed to open area, traveled 500 ft, crown was 2-3 ft, 200 ft across at largest area, debris pile 250 ft across 5-10ft deep, broke trees 8” in diameter,

Small slides in glades the entire way to the Gothic Road, Second slide propagated into exposed 34 degree slope, from tight trees, could have also buried skier in opening

Snowpack: Very unstable, it may have been an isolated area, but there were point releases all the way down to the Gothic Road in the glades (tight trees, pocket releases, around anchors), a little wind blown layer on top, facet layer 2-3 feet deep. 32-42 degree slope angles,

Most unstable snow pack I’ve skied Snodgrass in, probably been up there 30 times over 7 years.

No prior ski compaction

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