snow on rocks, or dirt, or grass, or sharks

Location: Paradise Divide Area
Date of Observation: 12/29/2017
Name: Evan Ross

Subject: snow on rocks, or dirt, or grass, or sharks
Aspect: East, South East, South
Elevation: 9,500-12,560

Avalanches:

Checked out the Augusta avalanche reported after the Christmas Storm. In a pit below the crown about 100ft and off the left side of its flank the HS was about 60cm’s. Basically, the Christmas Storm was sitting on the 12/23 wind event and denser snow, down to the ground. Any previous snow was poorly distributed through the rocky terrain. ECTN at this interface on small decomposing grains. The Augusta natural avalanche appeared to fail on this interface and not at the ground. The avalanche size was an R1 in the terrain, while debris where difficult to map as the snow surface has blown back over and been blended back in.

Weather: Few clouds in the morning becoming clear by afternoon. Moderate westerly winds at 12,560.
Snowpack: On south and southeasterly facing slopes there wasn’t much difference in snowpack structure from 9,500ft up to 12,560ft, other then snowpack depth. ECTX at 11,200ft on SE facing 33 degree slope. ECTN at 12500ft on SE facing 36 degree slope. Small column tests could produce resistant shears below the Christmas Storm on non-persistent decomposing small grains. On these aspects throughout the elevation traveled the snowpack begin with the 12/21 storm.

Turned around on one ENE facing slope that was a small roller in the terrain. As the snowpack doubled in hight with very weak snow below stronger snow….

Photos:

Slab avalanche that failed during the Christmas Storm on a steep easterly facing slope just below 12,000ft. A more recent loose dry avalanche can be seen lookers left.

Turned around on this easterly facing slope that was a small roller in the terrain. As the snowpack doubled in hight with very weak snow below stronger snow….

Snowpack at about 11,500ft on a southeasterly facing slope. Any snow previous to 12/21 was very thin and poorly dispersed through the terrain.0

Snowpack at 11,000ft on a southeasterly facing 30 degree slope.

Snowpack at 12,500ft SE aspect. Basically, the Christmas Storm was sitting on the 12/23 wind event and denser snow, down to the ground. Any previous snow was poorly distributed through the rocky terrain. ECTX on the 12/23 interface on small decomposing grains.

Natural slab avalanche that likely failed near the end of the Christmas Storm. NNW aspect at 11,400ft.

Wet avalanche debris below a southeasterly facing terrain i the upper Middle Anthracite Creek.

Snowpack coverage on the north face of Augusta Mountain. Cross loaded or blown out was the theme.

Looking up at the Augusta avalanche that failed during the Christmas Storm.

Persistent Slab structure harder to find but still there

Location: Crested Butte Area, Washington Gulch
Date of Observation: 12/28/2017
Name: Evan Ross, Avalanche L1 Class

Subject: Persistent Slab structure harder to find but still there
Aspect: North East, East
Elevation: 9,700-10,900

Avalanches:

Searching for the right slopes produced shooting cracks and a collapsing snowpack but slope angles for two low for an avalanche to release.

Weather: Light northwesterly winds at ridgeline. Mostly clear sky.
Snowpack: Still a sensitive and spooky snowpack, but those locations are getting harder to find with each passing day. In this area, below 10,200ft the snowpack was effected by previous down valley winds. Windward features had a thinner snowpack that lacked PS structure. The cross-loaded terrain features that faced more ESE had better slab development but lacked much for weak layers below those slabs. Climbing above 10,200ft on an easterly facing aspect the snowpacks became deeper, partly because the slope was more protected from the wind. With PS structure becoming better developed and more widespread. We quickly transitioned into a snowpack that showed obvious signs to instability with collapsing and shooting cracks. We searched out a more shaded slope with more consistent snow coverage and were able to collapse the entire slope from the nearby trees with a small pocket slumping down hill.

At all elevations we traveled, the PS structure is breaking down as the upper slab has been faceting out.

Photos:

Traveling in the trees near this slope produced shooting cracks through the entire slope with this small slump down hill. The slope was concave and in the low 30 degree range.

Cross-loaded terrain features below 10,200 feet. Thin and faceted snowpack on the windward slopes. Wind-loaded slabs didn’t have much for weak layers below. given the thin previous snowpack.

Friends Hut observations

Location: Brush Creek Area
Date of Observation: 12/27/2017
Name: Ben Pritchett

Subject: Friends Hut observations
Aspect: North East, East, South East, South, South West
Elevation: BTL-NTL

Avalanches:

Saw d2.5 off baldy’s east face skiers left of Rock cr bowl. 2x D1.5’s off big timbered hill east bowls.
Saw a moose triggered D1 slab 70’ wide at the bottom of the hill below the hut.

Weather:
Snowpack: ALL SENT FROM INREACH DEVICE.

HS 70cm; HST 25cm. 4F HST over F interface. Reactive cracking off the trail.

Photos:

Remote trigger Paradise Divide

Location: Paradise Divide Area
Date of Observation: 12/27/2017
Name: Eliot Rosenberg

Subject: Remote trigger Paradise Divide
Aspect: North, North East
Elevation: 11,000, NTL

Avalanches:

remotely triggered D1.5-2 in Purple Palace area on ascent, failure occurred at our same elevation, one small ridgeline over from our approach.  We heard and felt the collapse/release.  It ran at least 1500 feet, creating 6+ feet of debris.  Roughly a 2 foot crown, wide propagation and shooting cracks above the failure.  Also, this is the first prominent northerly slope running to the purple palace bench.

Weather:
Snowpack:

Photos:

Anthracite Avalanche – Remote trigger

Location: Kebler Pass Area
Date of Observation: 12/26/2017
Name: Chris Martin

Subject: Anthracite Avalanche – Remote trigger
Aspect: North
Elevation: 11,000′

Avalanches:

R4-D1.5-2 Remote Trigger from adjacent slope, lookers left of crown about a 20-30 meters away (see photo).

Weather: Partly Cloudy -2C. Light winds.
Snowpack: Not Recorded. Persistent slab ID’d on adjacent slope, 20 cm depth hoar at ground(N-NW), lookers left of crown .

Photos:

Recent D2 avalanches

Location: Crested Butte Area
Date of Observation: 12/26/2017
Name: Ben Pritchett

Subject: Recent D2 avalanches
Aspect: East, South East

Photos:

Tale of Two Snowpacks

Location: Paradise Divide Area
Date of Observation: 12/26/2017
Name: Dustin E.

Subject: Tale of Two Snowpacks
Aspect: North, North East, East, South East, South
Elevation: 9000-11800

Avalanches:

Lots of activity although most were pretty small. Saw multiple (7?) natural soft windslabs on Climax Chutes, Schuylkill, Schuylkill sub peak above Pittsburg, one on SE face of Augusta. All appeared to have slid on interface layer. All were D1. One slide in Redwell (West side) that I did not get a good look at but could’ve been D2. Most looked like they had slid mid-storm and had filled in again.

Weather: Warm in the morning and cooled off right around noon. SW Winds picked up (Moderate) with periods of blowing snow.
Snowpack: The snowpack on northerly slopes was yelling at us. Lots of collapses and cracking. Some collapses initiated from flats onto North slopes up to 20 meters away. As we transitioned onto more Easterly and Southerly aspects the snowpack quieted down and was generally right side up. HS on Northerly slopes was up to about 90 cm and much shallower on East and South( anywhere from 20-60 cm). Small surface crust developed in the day on East and South faces near and below treeline.

Photos:

Remote trigger cornice

Location: Crested Butte Area
Date of Observation: 12/26/2017
Name: Sam Higby

Subject: Remote trigger cornice
Aspect: North East
Elevation: 10,900

Avalanches:

Base surface was 40cm, most of the blocks and the crown were 100cm thick. Propagated around 150ft across ridge, went down into the trees and stopped. Photos below, feel free to ask me more questions.

Weather: Sunny, cool, breezy
Snowpack: In sheltered areas right at 100cm. Old snow from November was 40cm and faceting. Were on the ridge before Coneys and saw the cornice. I stopped to get my cord out to cut it and it dropped before I could do anything.

Photos:

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: