Anthracite avi activity after storm

Location: Kebler Pass Area
Date of Observation: 12/26/2017
Name: Eric Murrow

Subject: Anthracite avi activity after storm
Aspect: North, North East, East
Elevation: 10,000 – 11,500

Avalanches:

Numerous slides- multiple releases at top of east bowl(photo), several small rollovers half way up skinner(photo), numerous at head of Playground Basin(photos), and one remote skier triggered in Big Chute(photo)

Weather: Generally clear skies with few clouds about. Winds were light with no visible transport.
Snowpack: After the past weeks snow, sheltered terrain around the Anthracites, have settled new snow depths of 22cm to 35cm. Recent snow was still Fist hardness but certainly has begun to settle and become a bit more cohesive. In areas that saw wind deposits were definitely slab like with 4finger hardness.
Ski conditions were noticeably more supportive today. While skiing tree chute and sliver, cracks and collapsing were common. Even in well sheltered pitches. These instabilities were relegated to new/old interface, about 30cm down. We also experienced a large collapse at top of big chute. This collapse occurred below the most recent snow(this location has seen several loading events from wind prior to last weeks snow). The collapse propagated 100ish feet, basically the entire start zone of big chute. This collapse didn’t avalanche, but it did release a wind slab on furthest skiers left edge.

Photos:

Lot’s of whumps and cracking

Location: Paradise Divide Area
Date of Observation: 12/26/2017
Name: JT

Subject: Lot’s of whumps and cracking
Aspect: East
Elevation: 10,500

Avalanches:

None observed.

Weather: Windy and mostly sunny.
Snowpack: Hasty pit revealed a roughly 2-3 foot snow depth. Very slight wind crust on top. The top 3/4’s was fairly consistent and formed a really loosely bonded slab. The bottom 1/4 was straight sugar. It skied nice and was supportive to boot level. On steeper shots we noticed a lot of cracking, some cracks propagated over 10 ‘ to an adjacent slope. There really was not enough energy to make an avalanche, but I think that will change as the top portion forms into a more cohesive slab.

Photos:

Natural activity around Gothic

Location: Crested Butte Area
Date of Observation: 12/26/2017
Name: Alex Tiberio

Subject: Natural activity around Gothic
Aspect: North East, East
Elevation:

Avalanches:

With clear skies we were able to check out some slopes with binoculars. Crowns are visible on the E face of Gothic, at the top of an east facing gully below the largest cliff on gothic, as well as the top of 3rd bowl on Snodgrass. The latter of which looks like it released pretty deep in the snowpack, you can see dirt below the crown.

Weather: Mostly Clear skies
Snowpack:

Photos:

Widespread collapsing and cracking at Pittsburgh

Location: Paradise Divide Area
Date of Observation: 12/25/2017
Name: AH

Subject: Widespread collapsing and cracking at Pittsburgh
Aspect: North, North East
Elevation: 10,000

Avalanches:

Our group of 3 headed to Pittsburgh in search of low-angle and manageable terrain for a little Christmas day outing. Where the typical skinner heads into the trees, we got a large collapse on a small roller. Cracks everywhere with a little movement up top, but otherwise the snow held – it’s a small slope, convex roll, and short feature. The cracks propagated across the entire feature, at least 100ft. We poked around looking for a route higher, but we found the same thing higher on the slope. Every slope we approached that was at or near 30 degrees collapsed and cracked, or had already collapsed and cracked before we approached. Being buried from above or being smashed into a tree wasn’t on any of or wish lists, so we headed home to celebrate Christmas dinner with our friends.

Weather: Snowing all day, shifting between graupel and big flakes.
Snowpack: A foot or more of new snow landing on top of facets.

Photos:

Anthracites

Location: Kebler Pass Area
Date of Observation: 12/24/2017
Name: Jake Kay

Subject: Anthracites
Aspect: North
Elevation: 11,495

Avalanches:
Weather:
Snowpack: Dug pit on top of anthracite ridge. Found 70-80cm total snowpack. from ground up, found 15cm of depth hoar, than 20cm of finger hard slab that went at ect 24 q3. Followed by 10 cm of faceted snow with a small crust and finally 25cm of new snow which which had barely formed into a fist hard soft slab that went on ect4 q3

Photos:

East Ditch Trail

Location: Crested Butte Area
Date of Observation: 12/25/2017
Name: ZDK

Subject: East Ditch Trail
Aspect: North East
Elevation: 8900

Avalanches:

Small windslabs breaking on NE aspects, 35deg near town. 1 appeared to fail mid-storm, the other on facets near the ground.

Weather: S 1, Light-Moderate WSW winds, blowing snow.
Snowpack: Average HST 25 cm in sheltered areas.

Photos:

Gothic 7am Report

Location: Crested Butte Area
Date of Observation: 12/25/2017
Name: billy bar

Subject: Gothic 7am Report
Aspect:
Elevation:

Avalanches:
Weather: Steady snow overnight with little wind with 10″ new anow and water 0.57″. Snowpack up to 23″, winters deepest. Currently light snow as wind has started up in the past half hour. Wind could cause problems if it continues- currently light but gusting.
Snowpack:

Photos:

Some Cracking

Location: Crested Butte Area
Date of Observation: 12/24/2017
Name: Karin Pocock

Subject: Some Cracking
Aspect: East
Elevation: 9,700-10,800

Avalanches:
Weather:
Snowpack: Some cracking no further than 1-2m from ski tips, some “whumpfing” on small convexities on slope that produced cracks, but nothing else.
Generally the HS is roughly 40-60cm. On average it’s 30(ish)cm of FC and small DH with roughly 15-20cm HST from the last 48hrs sitting on top of it. In sheltered areas the whole snowpack is relatively homogenous in resistance F through 4F-. In wind effected areas it’s super variable, stripped to the facets, pencil hard 1-3″ wind skin/windslab on the surface, or deeper HST of variable densities from wind effect.

Photos:

When will the slab form?

Location: Paradise Divid Area
Date of Observation: 12/24/2017
Name: Evan Ross

Subject: When will the slab form?
Aspect: North East, East
Elevation: 9,700-11,300

Weather: Fairly calm down in the valleys with some moderate westerly winds near treeline. Mostly clear sky became overcast in the early afternoon.
Snowpack: Still no persistent slab avalanche problem, even with 12″ of new snow since Wednesday night sitting on a weak faceted snowpack below. When will this upper snowpack become reactive on its weaker base? Thats the big and scary question. Even were the upper snowpack was stiffened by Saturdays wind event it was still mostly unreactive in this elevation ban. Found two very small wind-loaded pockets the broke on the interface between our two recent storms but not on the weak faceted snow below. HS in this area was about 60-70cm at 11,000ft.

Open slopes at any elevation, but mostly above treeline saw what looked like more snow stripped away by Saturdays wind event then loaded onto the slopes. Cross-loaded pockets behind tree fences or vertical ridges seemed to catch the most snow.

This observation is from one of the deeper parts of our forecast area. The vast majority of slopes observed on the way to this area have a very, very thin snowpack.

Photos:

Gothic Mountain Seen from the WSW

Cinnamon Mountain Seen from the Southeast.

Very Small windslab breaking between the two recent storm interfaces and not on the weak snowpack below. ENE aspect. 10,200ft.

Snodgrass Obs

Location: Crested Butte Area
Date of Observation: 12/24/2017
Name: AT

Subject: Snodgrass Obs
Aspect: North East, East
Elevation: 10,400

Avalanches:

None

Weather: Clear skies in AM becoming cloudier
Snowpack: On the uptrack wind deposited areas had as much as 12″ of storm snow on top of the faceted base. Wind scoured areas had in the 2-3″ range. On descent we produced some shooting cracks in an areas with over 12″ of wind deposited snow.

Photos: