Pittsburgh Thursday and Friday

Location: Paradise Divide Area
Date of Observation: 12/07/2018
Name: MR

Subject: Pittsburgh Thursday and Friday
Aspect: North East
Elevation: 9,500-10,500

Avalanches:
Weather:
Snowpack: Thursday – hoar Frost on skintrack. No signs of instability.
Friday – skiing same terrain as Thursday, got 3 whoomphing collapses

Photos:

Variable Sensitivity

Location: Crested Butte Area
Date of Observation: 12/07/2018
Name: Evan Ross, Zach Kinler

Subject: Variable Sensitivity
Aspect: North East, West
Elevation: 9,800-11,000. BTL

Avalanches:

SS-AS-R1-D1.5-O BTL West Facing Aspect. Crown about 60cm with only about 5-10cm of 4f slab in there. Failed on large facets on the ground.

D2.5? Very large avalanche off an Above Treeline easterly aspect of Gothic mountain. Could only see parts of the crown and never saw the debris. Probably ran within the last 24hr.

SS-N-R1-D2 ATL on the southerly face of Mt Bellview. Looked like it ran in the upper snowpack as a windslab. Probably ran within the last 24hr.

Belleview Mountain South: SS-N-R2-D2-I (this is a different mountain than the one above.)

SS-N-R1-D2 ATL on an easterly aspect of Baldy Mountain. . Probably ran within the last 24hr.

Numerous small loose snow avalanches that ran today on upper elevation steep and rocky southerly faces.

Weather: Fog in the upper Crusted Butte Valley in the morning and moving out around midday. Otherwise few clouds. Calm winds. Good solar.
Snowpack: Variable sensitivity to the PS avalanche problem. On BTL north east, we got some good collapsing and shooting cracks up to 15ft on slopes in the lower 30 degree range. The couple of steeper slopes over 35 degrees we visited had previously avalanche this winter. The slopes that avalanched earlier in the winter had refilled and were tough to distinguish between those that hadn’t avalanched. In a profile on one slope that had previously avalanche, the HS was about 20cm’s less, lacked a slab, but maintained about 5-10cm of large grained facets on the ground. So difficult to tell which slopes or where on a slope the PS structure was present and currently reactive.

On a westerly aspect BTL and protected from the wind, the snowpack structure mirrored that of a NE aspect. Otherwise, the more open westerly aspects appeared thin and sharky.

Photos:

Red Coon & Red Lady Glades

Location: Crested Butte Area
Date of Observation: 12/07/2018
Name: TC

Subject: Red Coon & Red Lady Glades
Aspect: South East, South
Elevation: 9,200-12,200

Avalanches:

No new slab avalanches, but significant sloughing in RL bowl. Sloughs ran 800+ feet.

Weather: Low-lying fog in the morning (9:30), clearing by 11:00. Zero wind, temp in the 20s.
Snowpack: A few fresh inches on top of a melt/freeze crust in Red Coon glades. Still some collapsing ascending Coon Ridge to the summit. No remote triggers, but plenty of fresh loading in the NE terrain of Coon basin. Top 8 or 10 inches was already wet and heavy around 11,000 feet descending back into Red Lady drainage (11:00AM). Wet slides could be an issue on steeper slopes a little later in the day. Observed several fresh slough slides from wind transported snow in Red Lady bowl. Top half of the RL glades skied well while bottom half was wet, heavy & sticky. I imagine things will be crusty tomorrow after tonight’s refreeze.

Photos:

Gothic 7am Report

Location: Crested Butte Area
Date of Observation: 12/07/2018
Name: billy barr

Subject: Gothic 7am Report
Aspect:
Elevation:

Avalanches:
Weather: Cloudy, mild and calm with light but steady snow since sunrise Thursday, stopping a bit after midnight this morning. The 24 hour totals, assuming nothing in the next hour, has been 6″ new snow and 0.53″ of water with the snow pack currently at winters deepest of 27½”. Much warmer with the high 29F while staying around 20F overnight (currently 19F). Cloudy now but I did see a few stars pop out abut a half hour ago. Yes, the universe is still out there (of course the light I saw was millions of years old so who can tell).
Snowpack:

Photos:

Mt. Owen Profiles

Location: Kebler Pass Area
Date of Observation: 12/05/2018
Name: Tom Schaefer

Subject: Mt. Owen Profiles
Aspect: North East, South
Elevation: 11400′

Avalanches:

12/4/2018
#1 (Green Lake Gully Washer) N-SS-R2-D3-O
#2 (SE lookers right of GLGW) N-SS-R2-D2-O
12/5/2018
#3 (NE shoulder of Owen) N-SS-R2-D2.5-O
Appears all 3 failed on the Nov. 22 interface

Weather: Overcast throughout the day temps in the teens with steady moderate winds from the SW. ATL snow was continuously being transported onto lee slopes.
Snowpack: Headed out to Mt. Owen to check out 3 natural avalanches off Mt. Owen that occurred between the 4th and 5th. Ski pen 15cm, boot pen 65cm. Avg. HS on the bench below Owen was 120cm avg. Along Scarp ridge on the windward side was avg. of 30cm. of soft snow . Pack has become more supportive, but in general there is still plenty of snow available for transport.

Photos:

Human Triggered Avalanche

Location: Kebler Pass Area
Date of Observation: 12/06/2018
Name:

Subject: Human Triggered Avalanche
Aspect: West
Elevation: 10,800

Avalanches:

Human Triggered Avalanche. 2 caught and carried, none buried.

Weather: Temps were in the mid 20’s, predominately OVC skies, at the time of the slide S-1 squalls where passing through, although about 20 min prior to activity there was a very brief, but noticeably warm break in the cloud cover. Creeper wind loading previous days with minimal new snow.
Snowpack: We had a skier triggered slide on 12/6 at 2:30 PM, west facing, ~11,000’, mid 30’s slope, Sunset Left/Outer Limits Interface. ASu-SS-R1-D2-O  125cm max crown height, ~25’ wide and ran ~200’ in a very narrow path thru a few woods at the start zone, max debris around 150cm.   One guide was caught, lost gear and has a minor back injury, but able to work. We are grateful.

Control teams had been thru that zone (and surrounding runs) previous days with hand shots and 7lbAnfo Airblast shots (7lbs Info w 2lbs of Dyno) and singles.  That morning, our Control team had been thru Sunset Left with hand shots. We also placed Anfo charges on adjacent slopes, at that same elevation, that produced no results.  I personally skied just below the start zone that morning to check the area prior to sending packers in there.
Second lap, our team spread out a bit, Guide #1 went into an adjacent pocket. He noticed it was deeper then normal and proceeded to pull his shovel out to take a look at the structure.  One packer followed him in and then Guide #2 skied in, they all felt a collapse and the pocket pulled out above Guide #2 who was slightly below the other 2 skiers. Guide 1 grabbed his pack to put back on, lost his shovel, but had eyes on the whole time. Guide 2 and packer were caught, packer was tangled for a moment but found edges and skied out. Guide 2 fell forward, grabbed a tree, but was pulled off and somersaulted a few times down the slope before landing up right facing downhill in the debris pile. He was buried to his knees, lost all ski gear, and at the time, felt shaken but injury free. He later has been dealing with a sore back.

Photos:

Snodgrass obs

Location: Crested Butte Area
Date of Observation: 12/06/2018
Name: IG

Subject: Snodgrass obs
Aspect: East
Elevation: 10,000

Avalanches:

None observed

Weather: Snowing S1, little wind, warm temps approaching freezing. Began snowing a bit harder at 15:30
Snowpack: Traveling off the beaten path we observed widespread collapsing in large areas but observed no cracks. Weak structure near the ground with facets, over a crust on the ground. 4 finger above to fist near the top. HS 30-60 cms.

Photos:

West Brush Creek from Monday 12/3

Location: Brush Creek Area
Date of Observation: 12/03/2018
Name: Eric Murrow

Subject: West Brush Creek from Monday 12/3
Aspect: North East, East, South East
Elevation: 9,000′ – 11,000′

Avalanches:

Surprisingly only ID’d one slab through this terrain. Very small D1 tucked immediately below ridge top on NE aspect.

Weather: Cold day with mostly cloudy skies and light flurries. No accumulation. Winds were mellow at below treeline locations. Did not observer transport across higher terrain.
Snowpack: HS ranged from around 40 to 75 cm across terrain and variety of aspects. While walking through low angle meadows we were able to produce numerous collapses below Thanksgiving slab. A few of these collapses ran around 75′. The goal for this day was to identify if Persistent Slab structure existed in this shallower part of the forecast area. SE and S aspects below treeline were bare ground prior to Thanksgiving storm – structure consisted of 20cm 1F hard Thanksgiving slab on ground, 2 to 3cm melt/freeze crust capping Thanksgiving snow, top 25cm from the storm this past weekend. No real issues S and SE below treeline.
East and northeast were a different story. Much of this terrain showed thick melt/freeze crust at the ground from October snow, 15cm of 2-3mm facets from early November, 20-25cm 1F Thanksgiving slab, topped with 25cm low-density snow from last weekends storm. Structure out west Brush Creek on shady slopes mirrored areas in Kebler and Paradise Divide below treeline but snow totals were shallower and Thanksgiving slab is only 6″ – 10″ thick. The real concern in this area is collapsing below the Thanksgiving slab. The profile included below is for one such site. We were able to produce propagating results on NE @ 11,000′. Slabs are just thick enough and hard enough that avalanches are possible. We did not get up to the drifted near treeline terrain in this area, but looking through binoculars made leeward start zones look much deeper than below treeline.

Photos:

Fresh wind drifts at ridgeline

Location: Kebler Pass Area
Date of Observation: 12/05/2018
Name: Evan Ross

Subject: Fresh wind drifts at ridgeline
Aspect: East, South
Elevation: 9,500-11,500

Avalanches:
Weather: Overcast sky. Light to Moderate westerly winds drifting snow at ridgeline.
Snowpack: Traveled in this same area on 12/3. Measured HS at the same location as on 12/3. At 11,300ft, south aspect HS was 90cm. That was a 10cm drop since the last time I was there, but more snow has also fallen during that time so the drop would have been greater, compared to the unmeasured peak snowpack hight. Ski pen had decreased and the upper snowpack had gained strength in those couple days. On southerly facing slopes, our group of three observed no obvious signs to instability regarding a persistent slab issue. Put some hard ski cuts on a few southeast slopes as well, but otherwise chose to avoid skiing on those slopes.

At the near treeline elevation, near the ridge, there had been a good amount of wind-loading over the last few days. Pervasively northerly winds had loaded some good sized drifts over the top of the ridge, while today the westerly winds were cross loading the rips in the terrain. The drifts were thick to ski through, but didn’t budge under a few ski cuts. Still managed the terrain off the ridge with windslabs in mind.

On easterly facing slopes BTL, the obvious signs to instability had greatly decreased since 12/3. The PS structure was still there, but we were not getting the shooting cracks and booming collapses as often. Still chose to avoid slopes greater than about 32 degrees in this area.

Photos:

Fresh Drifts loading a south aspect at ridgeline. While todays winds were cross-loading snow across the ribs in the terrain. Plenty of fresh snow to move around.