Ruby Range Obs

CB Avalanche Center 2019-20 Observations

Location: Kebler Pass Area
Date of Observation: 01/08/2020
Name: Ian Havlick
Subject: Ruby Range Obs
Aspect: East, South East, South, South West, West
Elevation: 10-12,000ft

Avalanches: none.

Weather: Overcast skies in AM, then scattered skies with big jump in wind, late in day clouds redeveloped to overcast. West winds increased with gusts into the 60s this afternoon. Significant transport all elevations, thin windslabs developing late in day, but largely more distribution and sublimation than slab building.

Snowpack: no signs of instability, no crust formation, surface snow continues to facet. Recent bump in wind (re)moving any loose snow from all elevations

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Purple Palace

CB Avalanche Center 2019-20 Observations

Location: Paradise Divide Area
Date of Observation: 01/07/2020
Name: Zach Kinler and Eric Murrow
Subject: Upper Slate River Valley
Aspect: North, North East, East, South East
Elevation: 9,600′-11,000′
Avalanches: No new avalanches observed.

Weather: Bluebird, a gentle whiff of westerly wind would cool us off every once in a while, temps hanging in the mid-upper 20s.

Snowpack: HS in this area averaged ~165cm at 11k on shaded slope. Surface was generally soft with little wind effect in the sheltered terrain traveled however surrounding open slopes at all aspects have been ravaged by the wind either stripping and scalloping the surface or depositing thin hard slabs. Low angle aspects south of east were slightly moist midday while shady aspects remained dry with light surface faceting.  Shovel Tilt Test revealed the 1/1, or New Years storm interface, easily slides with 20cm of low density snow above.   Investigated the 12/24 interface which was down 50 cm with a Fist to 1F- slab resting on top. Snowpack tests on this layer were CT23 Q1 and ECTN17. The other interface of interest is the 11/20 Depth Hoar which is rounding with short column test producing a DT21 Q1 result, 30 cm above the ground.

Photos:

Quick lap out Poverty Gulch

CB Avalanche Center 2019-20 Observations

Location: Paradise Divide Area
Date of Observation: 01/06/2020
Name: Zach Kinler and Eric Murrow
Subject: Quick lap out Poverty Gulch
Aspect: East, South East
Elevation: 8900′ – 10750′

Avalanches:  Observed a couple small wet loose avalanches on steep SSW facing slopes at 9700′, 4x – D1. I would guess that these loosies were a day or two old. Could see some debris that came out of a NE facing chute on Cascade. This debris looked to be blown over by the wind so more like 3 or 4 days old, D1. Also noticed some small dry loose skier triggerd slides on a very steep, NE facing feature near the exit of Wolverine Basin by Gun Sight Pass Road around 9600′, D1.

Weather: From 10am to 2pm, the area we traveled through was mostly cloudy with a cloud bank flowing over the Ruby Range with very light snow. Areas closer to Crested Butte looked to have a mostly sunny day. New snow accumulations were just a dusting with gusty winds out of the west.

Snowpack: Traveled through open E and SE facing terrain. HS for E slopes below treeline around 130cm. Dug a quick hole on a drifted SE feature at 10750′ to look at a location that has a slab resting on top of the mid-December sun crust. At this drifted site there was 50cm of snow resting on top of 12/24 crust, up to 1f hard. The crust was 3cm thick on this 30 degree slope. ECTX for this crust slab combination. There was light faceting above and below the crust but not dramatic.  Hammering on slab after standard test produced a failure above the crust. Snow surfaces below treeline on SE, S, and SW had a thin, around 1cm, weak crust at the surface from warming two days ago.
We stomped on a handful of very small drifted SE and E test slopes in the area without result.

Anthracizzles

CB Avalanche Center 2019-20 Observations

Location: Kebler Pass Area
Date of Observation: 01/05/2020
Name: Elias Goutos
Subject: Anthracizzles
Aspect: North, North East, South, North West
Elevation: 10,000 – 11,500

Avalanches: None observed, but rollerballing on S facing slope under cliffbands.

Weather: Few clouds in the morning with calm winds, increasing to broken cloud cover by noon and 27 degrees at 11,500′. Around 15:00, sky cleared again and winds picked up light to moderate with snow blowing off ridge tops.

Snowpack: Not as wind effected as expected. Penetration of ski was ~10-20cm all day except for the brief period when we were on more open/exposed terrain NTL. Found stiffer more supportable snow in those areas.
Surface hoar was present throughout the entire tour except for on NW aspect. Fairly large in size near the sleds and a bit smaller as we traveled higher and higher.
South facing slopes were wind loaded but did not appear to be stiff or have a slab form yet. Snow was getting moist on sunnier sides.

Slate River Shady

CB Avalanche Center 2019-20 Observations

Location: Paradise Divide Area
Date of Observation: 01/05/2020
Name: Eric Murrow
Subject: Slate River Shady
Aspect: North, North East, East, South East
Elevation: 8900′ – 11400′

Avalanches: None observed

Weather: Comfortable air temperatures throughout the day. Partly cloudy skies on the increase during sunset. Winds at ridgetop ramped up around noon from WSW. Some flagging on a few of the highest peaks and slight transport on near treeline ridge.

Snowpack: Ascended east and northeast facing terrain and found fresh surface hoar growth up through ridgetop elevations.  6mm near valley bottom and only 3mm near 11400′; even southeast slope at 11200′ had small surface hoar around 1230pm when we passed through.
Poked a quick hole around 11k on a northeast-facing slope found an HS of 120cm; I believe this slope may have avalanched very early in the season as it appeared to be slightly shallower and weaker than expected. Performed ECT to test the facet layer that was buried at Christmas, but even with 40cm of settled snow above the interface(still mostly F hard with small bit of 4f) a slab has yet to form, ECTN 12 result. Quick shovel tilt test revealed interface beneath the New Years storm; this interface is only 12cm below the surface at this location as winds have stripped some volume in the past two days. Tested the 3mm to 4mm basal depth hoar with a Deep Tap test, DTM.
Snowsurface on sunny slopes became slightly moist below treeline in the afternoon.

Photos:

Mount Baldy South Bowl

CB Avalanche Center 2019-20 Observations

Location: Paradise Divide Area
Date of Observation: 01/05/2020
Name: Ian Havlick
Subject: Mount Baldy South Bowl
Aspect: East, South East, South, South West, West
Elevation: 9600-12600

Avalanches: 1 fresh windslab in west-facing Paradise Basin (above Paradise Mine), looked to have failed yesterday morning potentially? Hard to make out depth but 1-3ft deep, not failing on ground. Similar aspect to yesterday’s reported Gothic Persistent Slab.

Weather: Partly cloudy, turned overcast, and then back to partly cloudy skies after 1400. Quite mild and balmy until reaching near treeline where steady light to moderate WNW winds continued to blow.

Snowpack: Snowpack in terrain traveled was generally a mix of surface facets and wind ripple down below treeline, to sastrugi and pencil+ phone book hard slabs in the alpine. Did not dig profile but much probing with poles revealed as expected, stacks of melt-freeze crusts in upper 60cm, with small-grained faceted snow. No significant slabs in south-facing terrain BTL to ATL and skied center of bowl looking for wind ripple without any signs of instability.

Photos:

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COBC AIARE 2

CB Avalanche Center 2019-20 Observations

Location: Crested Butte Area
Date of Observation: 01/04/2020
Name: Evan Ross
Subject: COBC AIARE 2
Aspect: North East
Elevation: 9,500-10,500

Avalanches: On Gothic Mountain, several small loose snow avalanches ran out of steep south facing slopes near rock bands.

Weather: Most significant weather was the warm temps and increasing winds in the afternoon. We didn’t pop above ridgline until late afternoon, right when the winds seemed to increase from the west south west. Large snow plums could be seen off the high peaks.

Snowpack: At lower elevations, the HS was around 90cm’s with no concerning Persistent Slab structure left in the snowpack. Thin and firm wind slabs could be seen on the cross-loaded terrain at these lower elevations. As we climbed we chose to avoid several cross-loaded terrain features, mostly due to the increased HS and lingering potential persistent slab structure. As we moved higher the HS also increased and we found a better strong over weak structure. This persistent slab avalanche problem appeared to be either stubborn or unreactive to human triggering in the terrain. At 10,400ft near ridgeline. HS was 140cm. CT and ECT column tests didn’t produce results in the mid to upper snowpack at this location. The depth hoar at the bottom of the snowpack was too deep for these particular column tests.

Photos:

Snodgrass

CB Avalanche Center 2019-20 Observations

Location: Crested Butte Area
Date of Observation: 01/04/2020
Subject: Snodgrass
Aspect: North West
Elevation: BTL

Avalanches: Observed a slab avalanche on White Rock Mountain or adjacent peak. Looks to be a R2-D2 and may have resulted from cross loading from yesterday’s high winds reported in the forecast. This avalanche is visible from Snodgrass Parking lot but hard to see exact starting zone. Debris ran from side gully and piled up in main gully. See picture.

Weather: Few clouds. Calm. Air Temperature was 22 degrees in shade around 13:30.

Snowpack: Pit depth was 105 cm. Performed a compression test and had a CT 24 Q3 on the October layer. See pictures. Slope was 39 degrees and this pocket had not been skied yet. Pit photos and profile attached.

Photos:

Paradise Divide – natural avalanches

CB Avalanche Center 2019-20 Observations

Location: Paradise Divide Area
Date of Observation: 01/04/2020
Name: Eric Murrow
Subject: Paradise Divide – natural avalanches
Aspect: North, North East, East, South East, South, South West, West, North West
Elevation: 8900′ – 12000′

Avalanches: Hand full of natural avalanches from the past 24 hours. Several Wind Slabs and a couple of deeper, dangerous Persistent Slab. Good views down the spine of Ruby Mountains without seeing other significant recent naturals on E and NE aspects.
Gothic D2.5, West, NTL
Purple Ridge D2, East, ATL
D1, East, ATL x 3
Elkton Knob D1.5, West, NTL
Weather: Pleasant air temperatures, mostly sunny skies with moderate winds near and above treeline. Winds shifted from NW to almost SW throughout the day. As winds changed directions more snow transport was visible in the afternoon.
Snowpack: Traveled through east – south – southwest aspects below and near treeline in open terrain. Surface was a mix of smooth, breaker windboard and soft, textured dapple. While traveling above drifted near treeline, easterly terrain found stiff, pencil wind slabs up to 50cm thick. Stomped on a couple of these stiff wind slabs without result, but certainly avoided skiing on these in avalanche terrain. Our group of 5 regrouped on a low angled, drifted southwest facing slope and produced a deep, loud, and slope scale collapse. No crack was present but it seems like the collapse was on basal weak layers not the crust buried around Christmas time; HS was around 120cm. Drifted sunny slopes near treeline have begun to develop a slab resting above facet/crust combinations but are limited to wind loaded features.

Photos:

Snodgrass

CB Avalanche Center 2019-20 Observations

Location: Crested Butte Area
Date of Observation: 01/03/2020
Name:
Subject: Snodgrass
Aspect: South East
Elevation: 10600

Avalanches: R1D1 soft slab. Broke 8-10″ deep on weak 1″ crust above road cut

Weather: Partly cloudy. Moderate cold wind out of N/NW

Snowpack: 8-10″ m snow from most recent storm. Had enough cohesion to propagate a cracks and break as a soft slab on slopes near 35°.

Photos: