Beckwith Pass

CB Avalanche Center 2020-21 Observations

Date of Observation: 03/03/2021
Name: Mike Cooperstein

Zone: Northwest Mountains
Location: Beckwith Pass
Aspect: East, South East
Elevation:

Avalanches: Older D.5-D1 wet loose avalanches on E and SE aspects which likely ran over last couple days. We did not stick around long enough to see any new activity.

Weather: Bluebird and very warm.

Snowpack: Steep, east facing snow surfaces were noticeably moist at 10,200k at 9:00 am. Around 10 am on south facing slopes at 11k, the surface crusts just barely still supported the weight of a skier, and we’re beginning to soften up quickly. We ended up skiing NE facing slopes which stayed dry.

Photos:

Fresh Cornice Fall

CBAC 2020-21 Observations

Date of Observation: 03/03/2021
Name: Zach Guy

Zone: Northwest Mountains

Avalanches: (Info from an InReach Text)

2 fresh looking wet slabs SE ATL off Leahy Peak. (Aspen side). Hot rocky bowl. Probably today or yesterday. D2 to D2.5.

Robbins saw a recent PSa triggered by cornice fall on Carbonate.

Several Loose Wet Avalanches

CBAC 2020-21 Observations

Date of Observation: 03/03/2021
Name: Evan Ross Zach Kinler

Zone: Northwest Mountains
Location: Angle Pass
Aspect: North East, East, South East, South
Elevation: 9,700-12,000

Avalanches: Several loose wet avalanches. A few old ones and some that ran today. Not widespread and mostly D1 in size with a couple D1.5s. SE, S, SW aspects had the majority of the activity.

Weather: A light breeze at 12,000ft, otherwise no winds. Hot… my face hurts.

Snowpack: We didn’t end up having to manage any wet avalanche concerns. Between 10am and 12:30pm we traveled on south and southeast slopes up to 11,800. The upper 3 to 5cm of the snowpack was wet, while the snow below remained dry. By the time we traveled back through similar terrain the surfaces were starting to crust due to lower sun angles and/or shading.

We mostly traveled on E and NE facing slopes in the afternoon. Some east facing slopes had a crust on them in the afternoon, but were mainly traveling through soft cold snow. Where that snow was soft and cold the upper snowpack was weak NSF, or firmer wind effected snow surfaces.

The snowpack we traveled on was otherwise deep and we didn’t encounter much of a concern on the persistent slab avalanche front.

Wet n’ Wild

CB Avalanche Center 2020-21 Observations

Date of Observation: 03/03/2021
Name: Jack Caprio
Zone: Northwest Mountains
Location: Beckwith Pass
Aspect: North, North East, East, South East, South
Elevation: 10k-11k

Avalanches: Older D.5-D1 loose wet avalanches on E and SE aspects which likely ran over last couple days. We did not stick around long enough to see any new activity.
Weather: Bluebird and very warm.
Snowpack: Steep, east facing snow surfaces were noticeably moist at 10,200k at 9:00 am. Around 10 am on south facing slopes at 11k, the surface crusts just barely still supported the weight of a skier, and we’re beginning to soften up quickly. We ended up skiing NE facing slopes which stayed dry.

 

Photos:

Coneys

CB Avalanche Center 2020-21 Observations

Date of Observation: 03/02/2021
Name: Alan Bernholtz

Zone: Northwest Mountains
Location: Coneys nose
Aspect: North East
Elevation: 10,800

Avalanches: Small loose snow sluff avalanche right off the top. 15 cm deep on 33 degree slope. 40’ wide by 80 feet long.
Weather: Clear with a light westerly breeze. Temp was in the 20’s
Snowpack: 70-80 cm total height of snowpack. Fist on top with a density change in the mid pack to fist+ then large grain facets at the bottom. The surface facets slid on the density change. Fairly predictable.

Photos:

Slabs of the Wind

CB Avalanche Center 2020-21 Observations

Date of Observation: 02/27/2021
Name: Jared Berman, Zach Guy Jack Caprio

 

Zone: Northwest Mountains
Location: East Bowl of Schuylkill Mountain
Aspect: North East, East
Elevation: 9,300′ – 11,100′

 

Avalanches: We intentionally triggered 3 small (D1) wind slabs on skis. Slabs ranged from 3″-6″ deep and were relatively harmless to a person. No recent naturals were observed today.
Weather: Weather started off overcast with light winds from the west below treeline. As we traveled clouds broke apart enough to see surrounding terrain and mountains. Moderate winds existed near treeline and we observed active wind transportation from some ridgetops and trees.
Snowpack: Persistent slab structure still exists on northeast aspects below treeline, capable of propagating deep failures. A snowpit at 9800′ on a northeast aspect revealed a 140cm hard slab (1 finger to pencil in hardness) resting on top of weak 2-3mm depth hoar at the ground (12/10 interface). The bottom of the slab contains rounding facets (1/19 interface) that appear to be gaining strength and were not as reactive as the 12/10 interface when comparing two propagation saw tests. See photo below of the snow profile with propagation saw test results.

Surface instabilities was a whole ‘nother ball game. Shallow wind slabs existed on isolated features near treeline and were reactive under skis. Slabs were small though ranging from 3″-6″ deep. We did not observe wind slab size or distribution above treeline as we did not travel at that elevation.

Photos:

GMT course through Rock Creek

CBAC 2020-21 Observations

Date of Observation: 02/26/2021
Name: Jack Caprio, Zach Kinler, Jared Berman

Zone: Northwest Mountains
Location: From Top of the World, we descended rock creek drainage to gothic campground
Aspect: North, North East, East, South East, South
Elevation: 9,600-11,600

Avalanches: Fresh wind slabs on a cross loaded alpine south aspect above Rustler Gulch (see photo).

An older, persistent slab avalanche on an east facing slope about 200 ft. above the east river valley bottom (see photo).

Weather: Westerly winds and overcast skies made for a cold sled ride in the morning. As the day went on, the clouds cleared and temps increased making for a very comfortable weather day.

Snowpack: We dug below treeline on a NE facing slope a couple hundred feet above the Gothic campground. We found a very stubborn persistent slab problem. At this pit site, the January interface sits 75 cm below the surface, with a large 1F hard slab resting on top. The 12/10 layer, which consists of large grained (6 mm chained) depth hoar, makes up the bottom 35 cms of the pack, and doesn’t seem to be showing any signs of improving. Snowpit tests did not produce any failures even after a couple aggressive swings from the shoulder after proper ECT tests (CTN, ECTX, ECTX). An aggressive shovel shear after our ECT tests did produce failure at the top of the 12/10 depth hoar layer. We did not receive any feedback from the snowpack such as cracking and collapsing while traveling in previously untraveled terrain.

The snow surface continues the near surface faceting process on shady aspects (currently .3-.5 mm NSF). On solar aspects, the surface consists of a 1-2 inch thick MF crust capping small grained facets. Everywhere we traveled above treeline (NE, E aspects), the snow surfaces were very beaten up due to recent winds, and hold perfect faceplanting conditions.

 

Photos:

Anthracites

CBAC 2020-21 Observations

Date of Observation: 02/25/2021
Name: Jack Caprio

Zone: Northwest Mountains

Location: Anthracites
Aspect: North, North East, East
Elevation: 10k-11.5k

Avalanches: 1 D2 slab avalanche on a S facing slope in ‘the playground’ which I believe released due to a cornice chunk falling.
A couple small, wet loose avalanches on sunny slopes near rock bands that likely ran over the past couple days of warm weather.
Weather: Calm day. Sunny. Comfy temps
Snowpack: We mostly traveled on established skin tracks below tree line on N and NE aspects. HS ranged from 160-200 cms. Where I dug, the first concerning weak layer was >120cms below the surface. Snow pit tests produced no results at this site. No collapsing/ cracking all day.

Recent N winds produced noticeable scouring of surface snow in N facing exposed areas, and large cornice building/ loading on S facing start zones. In protected areas, small near surface facets continue to develop.

 

Photos:

The basement is still cluttered with junk

CBAC 2020-21 Observations

Date of Observation: 02/25/2021
Name: Zach Guy

Zone: Northwest Mountains
Location: West side of Ruby Range
Aspect: East, South East, South West, West, North West
Elevation: 9,700 – 11,700′

Avalanches: Nothing recent apart from a handful of very small wet loose sluffs. Plenty of previously undocumented large avalanches from the last widespread cycle (~February 13) at all elevations. We crossed a debris pile that was easily D3+ off of the southwest face of Ruby that only had about 6″ of snow on it, so I’m guessing it ran February 16. See photos.
Weather: Light westerly winds, no transport. Few clouds.
Snowpack: Targeted below treeline test pits hoping to see evidence that basal weak layers are gaining strength now that they have been buried by a deeper pack for a few weeks. Unfortunately, that doesn’t seem to be the case. The 12/10 layer is still large grained and angular, showing little signs of hardening or sintering. All test results propagated with sudden collapses, ranging from very easy to hard (ECTPV, ECTPMx2, ECTPH), 70 to 90 cm deep on depth hoar or large-grained facets on a crust. If there is anything improving the current structure, it is that the upper slab is faceting on shady aspects and meltwater is moving into the pack on sunny aspects, which should add some integrity when it re-freezes. I jumped on a few small, steep test slopes with no feedback, and we didn’t see any obvious signs of instability throughout the tour underfoot.

 

Photos: