Upper Slate River Valley

CB Avalanche Center 2019-20 Observations

Location: Paradise Divide Area
Date of Observation: 02/03/2020
Name: Eric Murrow and Evan Ross
Subject: Upper Slate River Valley
Aspect: North, North East, East, South East, South
Elevation: 9000′ – 11350′

Avalanches: none observed

Weather: Snowfall started at about 1130 at the head of Slate River Valley. Accumulations reached about 2″ by 330pm at 9600′. While returning to trailhead at 4pm snowfall intensity ramped up to S2 for a short period presumably about the time of cold front passage. Winds blew 10 to 20 mph with occasional stronger gusts from the southwest. The new snow was easily transported around.

Snowpack: Ascended solar aspects and found substantial melt/freeze crusts on S and SE aspects up through high point at 11350′. Crusts on due south were up to 5cm and fairly hard supportive to skis. Southeast crusts were around 3cm thick. Even east aspects developed thin, soft melt/freeze crusts this past weekend. South and southeast aspects through 11300′ do not look to pose a problem without a major loading event.

Poked around on a northeast-facing slope at 11300 that is susceptible to wind impact and found a snow height a bit over 200cm. Around 30cm deep, there were two interfaces that produced planar results but did not propagate in long column test; failures were on lightly faceted grains. The midpack at this location lacked any concerning interfaces and was quite dense up to pencil hard. Only superficially examined lower snowpack, but no obvious weakness was present while probing.

Warm and sunny

CB Avalanche Center 2019-20 Observations

Location: Paradise Divide Area
Date of Observation: 02/02/2020
Name: Eric Murrow
Subject: Warm and sunny
Aspect: East, South East, South, South West, West
Elevation: 9000′ – 10800′

Avalanches: A little family of small loose avalanches on southeast aspect of Cascade below treeline coming out of a steep rocky area. I would guess they ran on Saturday.

Weather: It was a warm balmy day with light winds below treeline. Occasional plumes and flagging were visible throughout the day off ridgetops and peaks, but no real loading.

Snowpack: By about noon old surface crusts had broken down from temps and solar on southeast and south aspects. Did not see any fresh loose avalanche activity today through about 230pm. Riding conditions became quite nice on sunny slopes below treeline. Skied and snowmobiled numerous small test slopes below treeline without any results other than some very minor roller balls.

Photos:

Friends Hut Obs.

CB Avalanche Center 2019-20 Observations

Location: Brush Creek Area
Date of Observation: 01/30/2020
Name: Tom Schaefer
Subject: Friends Hut Obs.
Aspect: East, South East, South, South West, West
Elevation: 9000-12000

Avalanches: Observed one small shallow wind slab 50′ X 100′ that ran sometime the night or morning of the 30/31 off Carbonate peak SE aspect 12,200′.

Weather: Clear becoming OVC over three days with a trace of snow the night of the 30th. Temps averaged in the teens with moderate winds at lower elevations and strong N winds aloft.

Snowpack: Lower elevations had an avg HS around 60-90 cm’s. Generally a very weak faceted snow pack with sun crusts forming on solar aspects. Snow surfaces remained cold and dry. Snow bridges up to hut in good shape.
Higher elevations in Star basin was a mixed bag that was becoming ravaged by the winds up high. Skied W-S-E aspects. Only observed snow pack lower in the basin avoiding the winds up high. Looked like lots of sastrugi ATL. NTL HS ranged from 60-130 cm’s. No signs of instability observed. W aspect weak faceted snow pack , S aspect pretty much the same with several weak crust layers mixed in there, E aspects pretty much the same? Surface hoar observed in sheltered shady areas NTL.

 

Cement Mountain tour

CB Avalanche Center 2019-20 Observations

Location: Cement Creek Area
Date of Observation: 02/01/2020
Name: Eric Murrow
Subject: Cement Mountain tour
Aspect: North, North East, West, North West
Elevation: 9000′ – 12200′

Avalanches: None observed

Weather: Cold valley bottoms in the morning gave way to moderate air temps by mid-day at all elevations. Winds were very light even above treeline, very comfortable conditions in the alpine. Thin, high cloud cover all day – filtered sunshine.

Snowpack: Surface Hoar was present on all open slopes on the north half of the compass from valley bottom straight to the top at 12200′.

Below treeline shaded terrain showed a snow height between 60cm and 80cm. Ski penetration ranged from 20cm to 35cm, boot penetration was to the ground. There is just enough strength in the top half of the snowpack for reasonable skinning and marginal riding but generally too weak for much of a slab avalanche problem below treeline.

As soon as we walked above a large drifted slope, we produced a collapse. This collapse failed in the middle of the snowpack on a very weak faceted layer capped with surface hoar. Test results at a nearby location produced CT5 SC & ECTP11 results failing in the middle of the snowpack beneath a slab that has been building over the past month. Slab hardness was up to 1 finger. see photo

Briefly poked into a northwest-facing feature at 12000′ and again found a weak snowpack that struggled to support skis with an HS at 9ocm – riding conditions were trap-door.

Alpine terrain on Cement Mountain was not nearly as wind-blasted as other parts of upper Cement and Brush drainages.

Photos:

Wind havoc and taylor slide

CB Avalanche Center 2019-20 Observations

Location: Cement Creek Area
Date of Observation: 02/01/2020
Name: Tim
Subject: Wind havoc and taylor slide
Aspect: East, South East, South, South West, West
Elevation: 12,800

Avalanches: Observed what seemed to be a fairly recent persistent slab on a south aspect of Taylor peak at around 12,800

Weather:

Snowpack: Generally thin, or non existent, rotten and wind hammered. The good stuff

 

Photos:

 

Wind Loading in Poverty Gulch Zone

CB Avalanche Center 2019-20 Observations

Location: Paradise Divide Area
Subject: Wind Loading in Poverty Gulch Zone
Aspect: South
Elevation: 10,000’

Avalanches: Multiple natural wind slab avalanches were releasing on south facing convex rollovers that had a crust. Wind slabs were releasing anywhere from 2 inches to 12 inches thick. Our party also triggered a wind slab while skinning uphill in low angle rolling terrain. These avalanches only ran up to 40 feet, not a lot of energy and not enough snow to bury a person, but enough to knock a person off their feet.

Weather: Very gusty winds, Moderate temperatures, cloudy skies becoming clear after noon.

Snowpack: South facing aspects had a crust, with active wind loading, creating slabs up to 1 foot thick by noon.

Photos:

Near and below Treeline Close to Town

CB Avalanche Center 2019-20 Observations

Location: Crested Butte Area
Date of Observation: 01/31/2020
Subject: Near and below Treeline Close to Town
Aspect: North East
Elevation: 9,000-11,200

Weather: Clear(ish) sky with very light, hazy clouds. Steady north wind at the ridge top. Single digit temps in the morning, climbing to around 20 by mid-day.

Snowpack: Fresh, shallow (6-8cm) and reactive windslabs on ridge features that are slow-moving and low energy, but could be problematic in high consequence terrain. Below 10,000 feet, snowpack is faceted, punchy and sloughy.

Snowed 3, blew into 6-10, skied like 8-14

CB Avalanche Center 2019-20 Observations

Location: Paradise Divide Area
Date of Observation: 01/31/2020
Subject: Snowed 3, blew into 6-10, skied like 8-14
Aspect: North East
Elevation: ATL, BTL

Avalanches: None seen but hard to see with bad light and snow whipping me in the face

Weather: Did I mention wind? Sustained with pulses bordering on ground blizzard approaching the ridge.

Snowpack: Anything facing east had a pretty good sun crust with new snow and windload on top of that. Massive snow transport up high, obviously. Everything else varied from wind scour, to wind ribs, to wind whales to sweet boot top goodness. While approaching the ridgeline, got a good crack that shot out about 30 feet into a slightly steeper slope but did not release. If you look closely at the photo, you will see… nothing.

Photos:

Mt Emmons wind load

CB Avalanche Center 2019-20 Observations

Location: Kebler Pass Area
Date of Observation: 01/31/2020
Name: JT
Subject: Mt Emmons wind load
Aspect: South East
Elevation: 12300

Avalanches: Wind loaded slab, didn’t progress very far.

Weather: Extremely windy.

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popped a small windslab. Also it was windy.

CB Avalanche Center 2019-20 Observations

Location: Kebler Pass Area
Date of Observation: 01/31/2020
Name: MR
Subject: popped a small windslab. Also it was windy.
Aspect: North East
Elevation: 11,000

Avalanches: unintentionally popped a small inconsequential windslab on an obvious convexity, 11,000′ NE aspect Baxter Basin, see photo. Light went extremely flat and mistakenly skied over the roll. Not a problem but points to potential for the problem in bigger terrain.

Weather: Big wind. Flagging off peaks, gusts swirling snow above treeline.

Photos:

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