12/4 Natural Avalanches

Location: Paradise Divide Area
Date of Observation: 12/04/2018
Name: Steve Banks

Subject: 12/4 Natural Avalanches
Aspect: East
Elevation: ATL/NTL

Avalanches:

Several recent natural avalanches were noticed on Whetstone Mountain (North Ridge of the M Face), Mt. Richmond (ran during the day 12/4), Purple Ridge, East ice of Mt. Owen (photo attached) and Mineral Point.

Weather: Sunny and cold with temperatures in the single digits. Winds were light at lower elevations but obvious flagging was noted off most peaks above 12,000′
Snowpack: On S-SW slopes below treeline the persistent slab structure was intermittent and seemingly unreactive. A crust above the Thanksgiving snow was found in some areas, but not all.

Photos:From Chris Miller

Mt Owen Avalanche

Location: Kebler Pass Area
Date of Observation: 12/04/2018
Name:

Subject: Mt Owen Avalanche
Aspect: East
Elevation: 12,200

Avalanches:

A large natural avalanche ran on Mount Owen around 9:30 am on 12/4. This D3 avalanche ran into Green Lake pushing water up and over its banks.

Weather: Sunny, Cold, high elevation winds moving snow
Snowpack: N/A

Photos:

Coney’s

Location: Crested Butte Area
Date of Observation: 12/04/2018
Name: David Neben

Subject: Coney’s
Aspect: North
Elevation:

Avalanches:

No signs of any previous slides

Weather: Perfect BlueBird but Cold, temp around 6 degrees
Snowpack: No signs of instability, cracks or collapsing on the climb, skied down the left side of the trees but not in the bowl where there were tracks.
The descent had previous tracks filled in but otherwise a clean slate with no obvious concerns.

Photos:

SW stable Pittsburgh

Location: Paradise Divide Area
Date of Observation: 12/03/2018
Name:

Subject: SW stable Pittsburgh
Aspect: South, South West
Elevation: 9200-11200

Avalanches:

Saw one very small crown @ 11000’ S facing on shallow convexity, appeared to be skier triggered by earlier group. Absolutely no other evidence of movement anywhere on entire aspect. No cracks, whumofs or apparent instability.

Weather: Squally ,NNW 15-20 kts up high constant light snowfall. Cold
Snowpack: 60-90cm w/ 45 cm fresh on top of TDay layer.

Photos:

Sketch on East, worked out on South

Location: Kebler Pass Area
Date of Observation: 12/03/2018
Name: Evan Ross

Subject: Sketch on East, worked out on South
Aspect: East, South
Elevation: 9,500-11,500

Avalanches:

Observed a few D2 soft slab avalanches that failed 1 to 3 days ago. These soft slabs failed at ridgeline around 11,400ft and propagated about 50% across the start zones, but were only R1’s relative to the whole avalanche path. Snowpits would suggest that they failed on top of the thanksgiving crust and the crowns have started filling back in. However they could have just failed within the new snow.

Poor vis so could only see terrain in the immediate area. 3X-SS-N-R1-D2 South facing slopes around 11,400ft.

Weather: Mostly Cloudy. Snowing S1 80% of the day. Calm wind, but didn’t really spend much time at ridgeline.
Snowpack: Definitely a play day, but some things are obvious even when you are not looking hard. To start they day, we were on an easterly aspect between 9,500 and 10,000ft. Big rolling collapses. Some shooting cracks but fewer than you would think. Just straight up avoided avalanche terrain here.

Spent the rest of the day on southerly facing slopes between 10,000ft and 11,500ft. Informally, just deep the whole time, wholly cow. The Thanksgiving crust and facets around that crust felt like the main issue. SE was more hollow and faceted below the crust, while south and southwest felt less likely to collapse the crust. The most likely avalanche problem felt like the snow above the Thanksgiving crust moving as a very soft slab onto of the crust. At 11,100ft, on a south aspect, the HS was 100cm! The Thanksgiving crust was down about 55cm with some small facets around the crust. A couple small collapses were felt on the shaded side of tree stands, otherwise know obvious signs to instability were observed on slope angels around 35 degrees on previously untraveled terrain.

Photos:

Red Coons Glades

Location: Kebler Pass Area
Date of Observation: 12/03/2018
Name: Will Nunez

Subject: Red Coons Glades
Aspect: South East
Elevation: 11,000

Avalanches:

No Avalanche where observed, lots of Whoofing and shooting cracks in low angle terrain.

Weather: Temp below freezing, light wind, clear to obscure skys, light to moderate snow fall.
Snowpack: HS ranged from 30cm to 80cm through out this area. The new storm snow has settled significantly. There where two concerning interfaces, a pencil hard crust with 2mm facets 15cm from the ground. And at 54 cm from the ground a 1-2mm facet interface F over 4F.

Photos:

stability on SW slopes

Location: Paradise Divide Area
Date of Observation: 12/03/2018
Name: Lawson Yow

Subject: stability on SW slopes
Aspect: South West
Elevation: 11,000

Avalanches:

No signs of instability. No cracks, whumpfs, or visible signs of avalanche activity.

Weather: Stormy
Snowpack: 60-100 cm deep
looking pretty uniform in hasty hand pits
Low angle pow

Photos:

Pittsburgh

Location: Kebler Pass Area
Date of Observation: 12/03/2018
Name: MR

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

Avalanches:

A few small debris piles presumably from storm snow instabilities over the weekend. No instabilities felt or seen today on or off the skintrack or while skiing.

Weather: Snowing S1 pretty much all day, cold, low winds
Snowpack: 3 inches new snow. Pole probing off the skintrack in the trees still showed little structure in the snowpack.

Photos:

Red Coon Glades – Whumphs and Shooting Cracks – Touchy Observations

Location: Kebler Pass Area
Date of Observation: 12/03/2018
Name: Chris Martin

Subject: Red Coon Glades – Whumphs and Shooting Cracks – Touchy Observations
Aspect: South East
Elevation: 11,000′

Avalanches:

N/O

Weather: calm , no drifiting snow observed.
Obscurred cloud cover
S-1 throughout the morning
Snowpack: Skied up through Coon glades today recognizing signs of instability, including whumpfs and shooting cracks that failed at similar depths on our tour up, all the way down to weak layer of facets. Weak layer did fluctuate characteristics on ascent. Appeared as Fist layer 10-15 cm of Basal facets at Pit #1 and changing to a Pencil hard 5cm frozen Layer crust at the ground with 2 mm facets above the crust. Test Results below. Great day to wiggle the low angle slopes.

Shooting Crack Pit #1:
HS 55cm SE Aspect 10,500′
F- 4F – F (top-Bottom)
Slab structure barely present but enough to whumpf, shoot a crack, and Fail on isolation of CT
Failures appearing on 10-15 cm layer of 1-2mm Basal Facets
CTV at crust above 10-15 cm layer of basal facets
No need for a Propagation test here, snow above column failed on isolation as well – see photos

Pit #2:
HS 70cm SE Aspect 11000′
F-4F-1F- P (top-Bottom)
Slab structure present in this pit
@30 cm from surface within storm snow CT 20 Q3 PC
@55cm from surface MFcr observed with 2mm FC directly above crust – PST 45 SF – See video
MFcr about 5 cm thick frozen at the ground

Photos:

Snodgrass Obs

Location: Crested Butte Area
Date of Observation: 12/02/2018
Name: Alex Tiberio

Subject: Snodgrass Obs
Aspect: North East
Elevation: 10,000

Avalanches:

None observed

Weather: Partly cloudy skies in AM light snow moving in around 3PM
Snowpack: Still whumping and collapsing. ECTP14 Q1 on a 33 degree slope failing on facets below the thanksgiving snow.

Photos: