Location: Crested Butte Area
Date of Observation: 03/04/2020
Name: Eric Murrow
Subject: Skier Triggered Avalanche Site Visit
Aspect: North East, East, South East
Elevation: 9,800′

Avalanches: Investigated the skier triggered avalanche above Long Lake. Aspect of avalanche was E and ENE. A side view slope angle estimate put the average steepness around 37 degrees. Crown depth along the flank (appeared to be near the average) was ~50cm. Total snowpack depth along flank was only about 125cm. The avalanche failed in a layer of weak faceted snow beneath a thin soft crust. The slab itself was relatively soft with hand hardness up to 4finger. Debris piled up deeply on the lake ice up to ~280cm in some places because of the abrupt change from steep slope to a completely flat lake surface.

The site of this avalanche is a good representation of a below treeline location that can still produce a dangerous avalanche. Relatively shallow snowpack, generally less than 140cm, with a soft slab present resenting on a pronounced weak layer.

Weather: Clear and warm with very light wind.

Snowpack: Overall the snowpack was very weak in this area; a ski pole, basket side down, could penetrate the snowpack full depth.

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Location: Crested Butte Area
Date of Observation: 03/03/2020
Name: Daniel
Subject: Skier triggered slide above long lake
Aspect: East
Elevation: 9800

Avalanches: Skier dropped off East facing ridge, triggered slide below wind loaded convexity beneath Aspen stand. No idea who skier was, noticed from meridian neighborhood. Large slide, tracks appear outthe bottom towards Washington gulch trailhead. May go up there with a beacon anyway.

**CBAC forecaster note** – a single track was observed entering slide and a single track was visible leaving the debris pile on the lake by observers other than reporting party

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Location: Kebler Pass Area
Date of Observation: 03/03/2020
Name: Tim
Subject: Snowmobile Remote Triggered Avalanche
Aspect: East
Elevation: 10,700

Avalanches:
Evans Basin
SS-AMr-R2-D1.5-I
35cmx50m (guesstimate)

Weather: CLR

Snowpack: Mixed bag of snow quality with cold dry, heavy wet, and thin crust.

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Location: Brush Creek Area
Date of Observation: 03/03/2020
Subject: Fresh Natural in West Brush
Aspect: West
Elevation: 11000

Avalanches: Natural. Looks to have run late 3/2 or morning of 3/3 See pic. Also appears that the south face of Teo went again.

Weather: Clear skies. Moderate winds low in the valley to higher gusts in the alpine. Moving snow on ridge tops. Wind eased off by 1:00pm.

Snowpack: Mixed bag

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Location: Cement Creek Area
Date of Observation: 03/02/2020
Name: Ian Havlick
Subject: Cement Creek
Aspect: North, South, South West, North West
Elevation: 9000-11000

Avalanches: Pretty solid avalanche Gibson Ridge midday observed. Failed as storm slab or dry loose sluff and stepped down. Expanded from initial small storm slab observed 0800 to larger secondary avalanche midday. Debris looked size 2.  Also worth noting the moving snow scoured into older snow near the ground as it ran.  (previously observed, but different photo felt helpful)

Weather: Orographic and convective snow showers made their way out to cement during the afternoon, not enough to produce much additional accumulation, but enough to obscure surrounding terrain, unfortunately.

Snowpack: 6-8″ of new snow resting on top of mainly 3-6cm melt freeze crust from days prior. New snow seemed to be insulating crusts a bit and the crust interface was moist. South-facing areas new snow had cooked and consolidated to ~4″ and aside from some small sluffing, posed no threat in terrain traveled. Winds had transported new snow a bit in more exposed areas, 1-2 foot slabs directly adjacent to exposed ridges, 4F with some cracking extending 5-10ft in front of skis. Overall structure remains concerning on all but true south in cement area with 4mm depth hoar below slabs 1-3 feet deep. Lower elevation south-facing not all that concerning as much of those aspects are starting to really cook-off and consolidate

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Location: Paradise Divide Area
Date of Observation: 03/02/2020
Name: Eric Murrow
Subject: Storm Day Obs
Aspect: North East, East, South East
Elevation: 9000′ – 10500′

Avalanches: Visibility was obscured and/or teasing all day with tough definition out Slate River Corridor. Smallish debris piles beneath Climax observed but could not confirm if Loose Dry avalanches or Storm Slabs. Lots of small Dry Loose avalanches observed near valley bottoms on steep shaded terrain. Observed two Storm Slabs on up-valley end of Schuylkill Ridge, D1’s. These looked to be half-filled in when observed in the PM.

On a drive up to Snodgrass TH in the evening just before sunset I was able to spy a few more significant slab avalanches above the Gothic Corridor. A real smorgasbord of avalanches…mostly dry loose, one obvious Wind Slab, Storm Slabs, and a Persistent Slab triggered by a shallow Storm Slab. Nearly all avalanche were D1-1.5 with only two slides reaching D2 in size.

Overall visibility greatly limited observations of the days natural avalanche activity.

Weather: Mostly cloudy skies from 1030am to 430pm out Slate River. Light snowfall was continuous throughout the day. At 130pm measured 19″ of new snow with 1.3″SWE (10500′). Winds were light at valley bottoms, but you could hear stronger winds at ridge tops.  Storm snow was noticeably settling during the day.  1.5″ snow accumulated between 11am and 4pm.

At sunset with better visibility, I could see active transport on to SE aspects on Red Ridge above Gothic. Alpine terrain in this area looked to have experienced a good amount of snow transport during the storm.

Snowpack: There was a clear density change in the bottom half of the new snow that was presumably responsible for the Storm Slab avalanches observed. It was easy to find this layer with simple hand shear tests, but even on steeper rolls around 35ish degrees, there was almost no cracking in the storm snow. Cracks never shot more than 2 or 3 feet.

Superficially touched a few SE below treeline slopes and found the new snow resting on a 3cm melt/freeze crust from this past weekend’s warm and sunny weather. Bonding between the new and old snow appeared to be good on these slick surfaces at this location.

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