Bluebird views

CBAC December 30, 20202020-21 Observations

Date of Observation: 12/30/2020
Name: Zach Guy

Zone: Southeast Mountains
Location: Coney’s
Aspect: North East
Elevation: N/BTL

Avalanches: Good views of the leeward aspects of the Northwest Mountains. Plenty of evidence of storm slab instabilities that ran throughout the storm, D1 to D2. A few slides looked like they broke into deeper layers, up to D2.5. Attached photos highlight the largest or most interesting activity.
We triggered a small storm slab (1 foot thick) on a rollover.
Weather: Clear, cold, calm winds.
Snowpack: Stepping off the beaten track we got frequent rumbling collapses and shooting cracks on basal weak layers. On shady aspects, we also got cracking at the storm snow interface about a foot down.

Photos:

: Rumbling collapses and shooting cracks were common when we got off the beat track

: The largest slide we could see was on Purple Ridge. NE ATL D2.5, likely broke as a persistent slab

: Skier triggered storm slab on a small rollover. D1

: Schuylkill Peak, NE NTL D2. Shallow sluff stepped down to a slab

: Schuylkill Peak, NE NTL, D2 storm slabs

: Redwell Basin, N ATL, numerous storm slabs to D1.5 and what looks like a D1.5 persistent slab

: Gothic SW ATL D1.5 storm slab

: Baldy SE ATL D2 storm slab

Avalanche Hunting

CB Avalanche Center December 30, 20202020-21 Observations

Date of Observation: 12/30/2020
Name: Zach Kinler
Zone: Southeast Mountains/ Northwest Mountain

Avalanches: Many avalanches from D1-D2.5 were observed at all elevation bands in both the Southeast and Northwest Mountains. Some failed around the new/old interface with crowns around a foot thick while others failed on the 12/10 interface with crowns 2-4 ft thick. East aspects were the most active benefiting from the combination of fragile buried weak layers and loading from recent westerly winds. Check out the pics below for a better idea of what failed and where.

Weather: Sunny skies, moderate to strong NW winds were observed in the upper Cement area with snow transport along ridges and peaks early this morning.

: Double Top North ATL D2, East NTL D1.5

: Double Top East ATL D1.5

: Teocalli Ridge East BTL, 10x D1-D2

: Middle Brush East NTL, 3x D1.5-D2

: White Rock, ENE ATL D2

: Teocalli Mt, East NTL D1.5

: Twin Lakes, ENE ATL D1.5 and D2

: Middle Anthracite East ATL, D2.5 and D2

: Middle Anthracite East NTL, 5x D2 and 2x D1.5

: Mt Baldy East ATL, many D1-D2 avalanches

: Beckwith East ATL, D2

: Beckwith ENE NTL/BTL 2x D2 and D1.5

: Just north of the CBAC forecast zone in the Crystal Drainage, E-NE ATL 6x D1.5-D2

: Just south of the CBAC forecast zone, Castles NW NTL, D2

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Email ob from Red Lady skin-track

CBAC December 30, 20202020-21 Observations

Date of Observation: 12/30/2020

Zone: Southeast Mountains
Location:
Aspect: South East
Elevation:

Avalanches: The photo below was taken at approximately 11 am on Wednesday, 12/30. From the skin track on Red Lady above tree line, a party of three of us saw two skiers come down the bowl, stop for a while in the circled spot, and remotely triggered the slide spotted lookers left to them maybe a minute or two after they had stopped there. We weren’t sure if they had stopped there for a particular reason and/or if they had noticed the remote slide. (Submitted by CBAC Forecaster from an email)
Weather:
Snowpack:

Photos:

Evans Basin

CBAC December 30, 20202020-21 Observations

Date of Observation: 12/30/2020
Name: Eric Murrow

Zone: Northwest Mountains
Location: Evans Basin steep easterly shots
Aspect: East, South East, South
Elevation: 9,500′ – 11,200′

Avalanches: A couple of avalances in steep southeast terrain in Red Lady glades – near treeline type features. Look like storm slabs running on the old crust. Likely failed very early AM of 29th.
One D2 at the very end of Moonscape Ridge by Evans basin – ENE-facing very drifted BTL feature
Weather: Ugly cold at valley bottom in the morning, but comfortable temps near and below treeline in the sun. No snow transport observed on nearby high terrain.
Snowpack: Solar radiation moistened the snow surface on SE, S, and SW slopes up to 11,200′. Made for interesting breaker-crust skiing at 3pm once it started to refreeze. Relentless collapsing on low-angled terrain on the ascent. Lots of collapses on flat ridgeline above steep east-facing slopes but very little cracking and no resulting avalanches, hmmmm. Skied down a short steep east-facing slope without result, but probing sure confirmed the suspect structure below. Dug a couple of test profiles checking on SE facing features to see if the crusts below the new slab is a potential Persistent Slab problem; slab seems not quite cohesive and heavy enough to cause an issue at locations traveled up to 11,200′, BUT a disconcerting double-crust setup exists below the slab. Recent storm snow was around 30 – 35cm thick but still Fist to Fist+ hard and bonding poorly to the crust below (see photo). On collapse ran 100+ feet and shot cracks across a tiny NE-facing slope down to the 12/10 interface; upon inspection Surface Hoar (~5 – 8mm) was found below the recent storm at the likely 12/22 interface. Easily ID this interface with shovel tilt’s tests.

Photos:

: Natural avalanches in Red Lady Glades area from early AM on 12/29

: Closer shot of Red Lady Glades natural avalanches

: Below treeline (slope receives drifting) avalanche at bottom of Moonscape Ridge (Evans Basin)

: Test profile from southeast slope at 11,000′

Gothic obs

CB Avalanche Center December 30, 20202020-21 Observations

Date of Observation: 12/30/2020
Name: Alex Tiberio

Zone: Southeast Mountains
Location:
Aspect: North East
Elevation: 10,500

Avalanches: A couple fresh naturals ran today near the snodgrass gothic saddle sometime between 10 and 2 and saw another older slide below gothic road closer to the snodgrass trailhead
Weather:
Snowpack: Talkative. Large collapses if going off the ski track

Photos:

RMBL Study Plot 12/30/20

CB Avalanche Center December 30, 20202020-21 Observations

Date of Observation: 12/30/2020
Name: Alex Tiberio

Zone: Southeast Mountains
Location: Gothic Townsite
Aspect:
Elevation: 9500

Avalanches:
Weather:
Snowpack:

Photos:

frequent shooting cracks & collapses RLG

CB Avalanche Center December 30, 20202020-21 Observations

Date of Observation: 12/30/2020
Name: jeff banks

Zone: Southeast Mountains
Location: RLG to Gravel Pit
Aspect: East, South East, South, South West
Elevation: 9,400-12,000

Avalanches: 4 older avalanches from ~10,800-11,200. from tail end of storm around 1-2 inches of snow on the old debris/bed surface in the “W” bowl between standard skin track easy glade line.
Weather:
Snowpack: Barking snowpack. Can’t move without Small to Large collapses skiing in less disturbed areas. Shooting cracks 3-15m NTL & BTL SE-S-SW all the way down to Kebler road. Slopes cracking up to ~38* but not releasing. Seeing some aggressive terrain choices out there for how vocal the snowpack is. Via con dios amigos.

Purple People Eater

CB Avalanche Center December 30, 20202020-21 Observations

Date of Observation: 12/30/2020

Zone: Northwest Mountains
Location: Slate drainage
Aspect: East, South East
Elevation: ATL

Avalanches: A lot of natural avalanches, huge on purple and one on gothic.
Weather:
Snowpack: Shooting cracks and a couple large collapses while breaking trail.

Photos:

Nasty natural

CB Avalanche Center December 30, 20202020-21 Observations

Date of Observation: 12/30/2020
Name: Sam L

Zone: Northwest Mountains
Location: Upper slate
Aspect: North, North East
Elevation:

Avalanches: Observed a new large natural in Baxter basin.
Weather: Cold and clear. Traveling uphill on southerly slopes was very warm but with little discernible change in snow surface.
Snowpack: Traveling up hill through north facing terrain produced several large and rumbling collapses with shooting cracks running hundreds of feet (see photo). Skiing southwest terrain we traveled through 12 to 15 inches of consolidating storm overlying a stout sun crust.

Photos: