A few avalanche observations

CB Avalanche Center2020-21 Observations

Zone: Northwest Mountains

Location: Ruby Range

Date of Observation: 12/13/2020

Name: Ben Pritchett

 

Subject: A few avalanche observations

Aspect: North East, East

Elevation: Near and above treeline

Avalanches:

Avalanches
Date Location/Path # Elev Asp Type Trig SizeR SizeD
View 2020/12/13 † Mount Emmons 1 TL NE SS N R1 D2
View 2020/12/13 † Ruby Range 1 >TL NE SS N R2 D2
View 2020/12/13 † Ruby Range 2 TL NE SS N R2 D2
View 2020/12/13 † Ruby Range 1 TL NE SS N R1 D2
View 2020/12/13 † Ruby Range 1 >TL E SS N R1 D2

Weather:

Snowpack:

Photos:

Gothic obs

CB Avalanche Center2020-21 Observations

Zone: Southeast Mountains

Location:

Date of Observation: 12/13/2020

Name: Alex Tiberio

 

Subject: Gothic obs

Aspect: North, North East, East

Elevation: 10,500

Avalanches:

15 or so naturals ranging from D1 to D2 from 1st bowl to the flanks of Gothic

Weather:

Snowpack: Winds overnight creates some big patches of wind board. More collapsing and cracking on our tour including areas we traveled yesterday that had already collapsed, especially where winds deposited a lot of new snow.

I thought it snowed?

CB Avalanche Center2020-21 Observations

Zone: Southeast Mountains

Location: Red Coon Glade

Date of Observation: 12/13/2020

Name: Steve Banks

 

Subject: I thought it snowed?

Aspect: South

Elevation: 11,600

Avalanches:

Saw a couple mid storm crowns on Axtell and I’m RLB. None looked bigger than D1.5 though they were quite filled in. These were on NE,E and SE facing slopes Above TL.

Weather: So hot in the sun. So cold in the shade. Barely a breath of wind. I thought I saw a cloud but it was just my judgment. I did see some flagging off of Beckwith in the late afternoon which I found a little surprising given the lack of wind where I was.

Snowpack: Thin! Solar slope BTL had little old snow except where shaded by trees. I found a little bit of moist snow and a little bit of a new crust forming, but only in 30+* slopes. In a few lower angle slopes there was old snow which was a confused mess of large faceted grains and up to 2 older crusts. Recent snowfall amounted to about 6-8” depending on elevation. I wouldn’t be surprised if some S-SW slopes got a new surface crust today.

Snodgrass slides

CBAC2020-21 Observations

Zone: Southeast Mountains

Location: Snodgrass

Date of Observation: 12/13/2020

Name: billy barr

 

Subject: Snodgrass slides

Aspect: North East

Elevation: BTL

Avalanches:

See photos of some slide activity on Snodgrass Mountain.

 

Weather:

Snowpack:

Photos:

Washington Gulch

CBAC2020-21 Observations

Zone: Southeast Mountains
Date of Observation: 12/13/2020
Name: Colorado Backcountry Avalanche L1
Aspect: North East, East
Elevation: 9,500-10,500

Avalanches: Many natural avalanches on below treeline slopes facing east to northeast. In general, the south side of Washington gulch has natural avalanche activity down by the reservoir and homes, on up to Coneys and beyond. These avalanches ran on Friday or Saturday. Many of those avalanches were small, a few where large in size. All appearing to release on old weak snowpack.

The above treeline Southwest Flanks of Gothic Mountain had 2 large windslab that ran early this morning.

Easterly and southeasterly terrain above treeline on Mt Baldy had one large persistent slab, and one smaller slab that may have released yesterday.

Weather: Clear, Cold, Calm.

Snowpack: Last night’s wind event was very evident looking around. In the Coney’s area, the winds mostly cross-loaded and blew up the terrain. The resulting wind-boards trashed much of the skiing, unfortunately. The new snow was notably thicker today, compared to yesterday. The persistent slab avalanche problem was less reactive than yesterday, but still making noise with collapses and shooting cracks while traveling on terrain less than 30 degrees.

Coneys

CBAC2020-21 Observations

Zone: Southeast Mountains

Location: Coneys

Date of Observation: 12/13/2020

Name: Jack Caprio

Aspect: North, North East, East

Elevation: 10,800

Avalanches:

From the ridgeline, skier remotely triggered a R1D1.5 persistent slab on a NE facing aspect near the treeline. The avalanche broke on a 1-inch thick melt-freeze crust about 14 inches down from the surface. Above the MF crust were 1-2 mm faceted grains which developed during our dry spell before Thursday. The slide entrained all the new snow from the most recent storm (about 14 inches) and propagated about 60 feet wide. The slab initiated on a > 30-degree start zone and the momentum quickly diminished as the slope angle decreased. All in all the avalanche ran about 150 vertical feet.

SS-AS-R1D1.5-I

Weather: Sunny and cold. Very subtle to no winds along ridgeline at 2 pm.

Snowpack: Last night’s winds towards the tail end of the storm cross-loaded many slopes. In open areas, the surface snow of breakable windboard ranging from 1-3 inches made for some very unenjoyable turns. Underneath the windboard was about 10-15 inches of F+ storm snow. On N aspects, basal facets made up the bottom foot of the snowpack. As soon as the compass rotated east of north, a melt-freeze crust with near-surface facets above it was found sitting below the new storm snow. This melt-freeze crust was the guilty layer/ bed surface of the skier triggered slab.

Photos:

 

Cycle in the Slate

CBAC2020-21 Observations

Zone: Northwest Mountains

Location: Slate River and Baxter Basin

Date of Observation: 12/13/2020

Name: Zach Guy and Eric Murrow

 

Subject: Cycle in the Slate

Aspect: North East, East, South East, South

Elevation: 9600′ to 11,700′

Avalanches:

Widespread natural cycle yesterday and last night: extensive soft slab naturals that broke 1 to 2 feet deep on the storm interface (12/10 facet layer). Slides ranged from small to large (D1 to D2.5); most propagated across much or all of their start zones and ran to mid track. I estimate that 90% of the north or east facing paths or features in Happy Chutes, Climax Chutes, and Schuylkill Ridge ran (roughly 60 slides), as well as the west facing near treeline terrain below Baldy and Gothic (about 5 slides). Last night’s winds obscured the evidence of avalanche activity in the alpine. There were some fresh crowns triggered by wind transport last night (about 5), but more commonly, evidence of activity during the storm was subtle and harder to characterize. The most notable was the east face of Mineral Point which ran to valley bottom.  In contrast, the southerly aspects that we could see showed minimal signs of avalanche activity.
Today we or other parties near us appeared to remotely trigger a handful of soft slabs up to 2′ thick. These were on small pockets or features so generally harmless in size.

Weather: Cold temps, clear skies, some light wind transport observed off of a few high peaks but calm winds where we traveled.

Snowpack: We observed widespread collapsing and shooting cracks while traveling on low angle terrain of various aspects. Some collapses were localized, some were rumbling and traveled 100 feet or more and would shake trees or trigger small pockets. Settled storm totals were 60 to 70 cm at low elevations, sitting on our well documented 12/10 interface. Low angle slopes with a southerly pitch were collapsing on a thin meltfreeze crust, or just facets on northerly pitches. On steeper southerly pitches, the crust is thick and uniform to the ground, lacking a problematic facet layer that is so widespread on other aspects or on lower angle slopes.
Not much evidence of wind transport during the storm, but last night’s northerly winds redistributed surface snow near and above treeline into some small wind slabs that didn’t react to ski cuts today.

Photos:

 

Anyone Can Ski Pow

CB Avalanche Center2020-21 Observations

Zone: Southeast Mountains

Location: Coney’s

Date of Observation: 12/13/2020

Name: Kirk Haskell

 

Subject: Anyone Can Ski Pow

Aspect: North East

Elevation: 12000 something

Avalanches:

Evidence of previous Avalanche Activity, no signs of current

Weather: Cold calm

Snowpack: Pretty stiff . One of those days where you’re psyched to run sweep so others can bust it up for you. Top to bottom windslab even in the trees . Going to be an interesting set up for next round of storms.

Ruby Natural

CB Avalanche Center2020-21 Observations

Zone: Northwest Mountains

Location: SE face of Ruby 12’000 feet

Date of Observation: 12/12/2020

Name: Tom Schaefer

 

Subject: Ruby Natural

Aspect: Southeast

Elevation: 12,000′

Avalanches:

N-SS-R1-D1.5-I
Southeast face of ruby approximately 150 wide and ran 1000′ most likely ran yesterday afternoon mid storm.

Weather: At Irwin village temperatures are in the low twenties. Clear skies and calm winds. Very nice!

Snowpack: HS 28″
HST 14″
Snow settled some last night with the cold temps. boot pen 40cm.
Along with the Ruby avalanche observed several steep road cuts and rollers around Irwin that had cracked to the ground naturally and slumped but did not run. Also observed two collapses in flat meadows walking on foot.

Photos:

Gothic 7am weather update

CBAC2020-21 Observations

Zone: Southeast Mountains

Location: Gothic Townsite

Date of Observation: 12/13/2020

Name: Billy Barr

Subject: Gothic 7am weather update

Weather: A steady dense cold weather snowfall all day Saturday with not a lot of buildup at 4½” new and 0.43″ of water as snow is at 21½” deep now. Thankfully there was little wind with it. The 24 hour period high was 15ºF and it is now at -14ºF, the coldest so far this winter. Currently clear and calm. The weight of the dense new snow should press on the lighter early snow. Storm total was 17½” of snow with 1.21″ of water. And now for a lovely, sunny day ahead. billy