Spring sprung early

CBAC2020-21 Observations

Zone: Northwest Mountains

Location: Upper Slate

Date of Observation: 12/05/2020

Name: Zach Guy

 

Subject: Spring sprung early

Aspect: North, North East, East

Elevation: 9700-12,300′

Avalanches:

Saw a few harmless (D1) dry loose avalanches that ran yesterday or today on east aspects from solar warming near rock bands and one that was animal triggered. Snowboarder triggered a very thin wind slab (D1) on a cross-loaded north-facing gulley, about 10 feet wide.

Weather: T-shirt weather at 12,000′ in the sun.

Snowpack: We traveled in steep terrain and found a generally quiet snowpack with a few small instabilities. At ridgeline there were isolated wind slabs up to 6″ thick from northerly winds earlier this week overlying well developed near surface facets. These produced localized cracking/collapsing in very small pockets in a few locations, and we triggered one small slab in a gulley. The snowpack is generally still supportive on to skis, you can find some terrain features with bottomless facets but the snow depth in those areas is too shallow to produce more than a small sluff, exemplified by the photo of recent naturals.
Surfaces in sheltered areas are generally 1 mm, fist hard facets. In the alpine, more wind texture and some variable wind crusts capping the facets, along with stiffer crusts below the facets from previous wind events: more of an abrupt hardness change.

Photos:

Tiptoeing in Baxter

CB Avalanche Center2020-21 Observations

Zone: Northwest Mountains

Location: Baxter

Date of Observation: 12/05/2020

Name: Joey Carpenter

 

Subject: Tiptoeing in Baxter

Aspect: North, North East, East, South East

Elevation: 9250-11.7

Avalanches:

A couple natural loose dry, very small initiating below cliff bands.

Weather: Bright and sunny, no wind and a beautiful day overall. Temps started around 10 degrees near Pittsburg and rose to above freezing. It was warm enough that even with the low sun angle, we were getting glop on the skins in the mid elevations around noon.

Snowpack: The snowpack is an inconsistent mess of facets with decaying midpack support (where you can find it). You’d be hard pressed to convince some people that it’s even ski season. We did find some fun, supportive turns but treading cautiously is essential. N, NE aspects in the mid elevation bands are completely faceted out. The mid-upper elevations offer better but again, inconsistent midpack support. Thin coverage on the more solar aspects makes skiing through lower elevation bands nerve wracking at best. “Every turn is a mystery, every knoll a surprise.” That about sums it up. Mid & upper elevation S, SW and W aspects visible from this zone are nearly devoid of snow now (Cinnamon, Mineral, Baldy, Purple Ridge) . Whatever is left will be gone if forecasts verify in the coming days.

The current state of the surface snow has very little ability to support a substantial load (if we ever get one).

More of the same…dry loose avalanches

CBAC2020-21 Observations

Zone: Southeast Mountains

Location: Climax Chutes

Date of Observation: 12/04/2020

Name: Zach Guy

 

Subject: More of the same…dry loose avalanches

Aspect: North East, East

Elevation: 11,300′

Avalanches:

Intentionally triggered about 8 dry loose avalanches from ridgeline, generally D1.5 with a few up to D2 in size. The sluffs started in the top 8″ to 10″ of faceted snow and plowed deeper as they ran further. Estimate they ran about 1500′ to 2000′ vert.

Weather: Clear, mild temps, calm winds.

Snowpack: Same old story. Weak faceted snow throughout the snowpack, generally fist hard. Decaying surface hoar in the top few inches of the snowpack produced some minor cracking where there were 2″ wind drifts. Snow gains a little cohesion as you gain elevation, and also is a bit more supportive in sparse trees compared to open chutes. The most reactive sluffing is in open terrain without tree cover. We avoided steep shady terrain because of both pushy sluffs and rock hazards and returned via a low angle ridgeline.

Photos:

found the facet sluff problem!

CB Avalanche Center2020-21 Observations

Zone: Northwest Mountains

Location: schuykill ridge – thanksgiving bowl

Date of Observation: 12/04/2020

Name: Mark Robbins

 

Subject: found the facet sluff problem!

Aspect: North East

Elevation: 9200-11400

Avalanches:

intentional ski cut on a convexity at 11,150′ on skier’s left side of thanksgiving bowl produced a loose dry avalanche or facet sluff which propagated 30 feet and ran 650 vertical feet, through small trees and exposing rocks below the snow, stopping on a bench in a stand of trees. Enough energy to take you off your feet and moving fast enough to hurt you in the trees or strained through rocks, not enough to bury you. See photo, have a couple videos which I’ll send to CBAC.

 

Weather:

Snowpack:

Photos:

Mt. Baldy

CB Avalanche Center2020-21 Observations

Zone: Northwest Mountains

Location: East face

Date of Observation: 12/03/2020

Name: Alan Bernholtz

 

Subject: Mt. Baldy

Aspect: East

Elevation: 12,400

Avalanches:

No avalanches were served but we did get a few collapses in isolated wind deposited snow on the approach. Very specific terrain features

 

Weather: Clear, cool, and moderate west winds on the summit

Snowpack: Variety of snow surfaces and depth. We experienced all kinds of snow conditions (except deep powder). At he deepest point the couloir held around 70 cm of snow but again, was a wide variety of depths. There was wind loaded areas and wind stripped areas. We found a few distinct crusts. A sun crust lower in the pack and wind board closer to the upper end of the pack and the surface was stiff from wind and sun. (Sounds horrible right but it was too bad) There were facets sitting on the ground, could possibly have been depth hoar but we did get too into checking it out but it felt well developed.
Mid mountain was scalloped shallow snowpack with near surface facets forming. The low revelation we found melt freeze supportable on south aspect. Yes, we hit rocks too.

Photos:

 

Below treeline in Northwest Zone

CBAC2020-21 Observations

Zone: Northwest Mountains

Location: Purple Palace terrain

Date of Observation: 12/03/2020

Name: Eric Murrow

 

Subject: Below treeline in Northwest Zone

Aspect: North, North East, East

Elevation: 9,600′ – 11,300′

Avalanches:

One small skier triggered Loose Dry avalanche.

 

Weather: Clear, sunny skies. Calm to light winds.

Snowpack: This was just a quick trip to look at the snowpack on shady terrain below treeline in the snow favored part of the forecast area. East facing slopes show very weak faceted snow at the surface resting on a faceting melt/freeze crust – challenging to skin on. Northerly slopes in this area range from 50 to 70 and remain supportive to boots and skis with relatively dense lower snowpack. Surface snow is losing strength each day. Shady, protected slopes over 38 degrees you can trigger small Dry Loose avalanches that do not gouge and entrain the top 15 to 20 cm. Great riding conditions.  The surface hoar that has been observed just beneath the surface in other parts of forecast area was spotty in this area – found two places that had it, but surface hoar was small and sporadic.

Photos:

 

Mount Axtel Weak Snow Junk Show

CB Avalanche Center2020-21 Observations

Zone: Northwest Mountains

Location: Mount Axtel

Date of Observation: 12/02/2020

Name: Eric Murrow

 

Subject: Mount Axtel Weak Snow Junk Show

Aspect: North, North East, East

Elevation: 9,500′ – 11,900′

Avalanches:

Intentionally triggered a couple small Dry Loose avalanches on north and east slopes near and below treeline. Loose dry avalanches did not fan out and spread, and entrained little mass, just enough to knock you over.

 

Weather: Cool day with light winds and some mellow gusts. Did not observe any significant transport of the couple inches of new from the previous day.

Snowpack: A weak and shallow mess. Snowpack ranged from 30 to 60 cm through this terrain. Areas less than about 45cm had little to no support to skis. Areas with 50cm or more still have snow at 4 finger hardness which provided a meager amount of support to skis. On all slopes traveled with open view to the sky there was buried, standing surface hoar, 6 – 10mm in size, underneath the few inches of new snow from the day previous.

East facing slopes were 1 -1.5mm facets that were fist hard with a faceting/decomposing crust in the middle. Small loose dry avalanches were easily initiated but were not quite able to gouge through the crust in the middle of the snowpack. Weakest snow observed was on east slopes just below the surface, 1.5mm solid facets.

Northerly slopes were well faceted, but generally a bit smaller grain size than east, ~1mm. We were able to easily initiated small Loose dry avalanches, but they did not gouge to the ground in most places.

Shaded near and below treeline terrain in this area is not functional for recreating. Depth of snow cover dictated snowpack support not elevation. There was a clear small Loose Dry avalanche problem, but the biggest threat to safety is attempting to ride through this shallow mess.

Photos:

 

Unhappy Chutes

CBAC2020-21 Observations

Zone: Southeast Mountains

Location: Happy Chutes, Mount Emmons

Date of Observation: 12/01/2020

Name: Zach Guy and Zach Kinler

 

Subject: Unhappy Chutes

Aspect: North East, East

Elevation: 9,000 – 10,300

Avalanches:

Intentionally triggered several long-running dry loose avalanches, large enough to drag or carry someone (D1.5). The slides entrained the entire snowpack (about a foot deep) and ran about 1000 vertical feet.

Weather: Mostly cloudy, light northerly winds, very light snowfall.

Snowpack: A shallow, weak mess. Snow depth is about a foot deep, almost entirely fist hard, 1 to 1.5 mm facets. The surface is 5 – 15 mm surface hoar (upright and intact) covered by the inch of snow that fell this morning. On east to southeast aspects, there is a decaying melt-freeze crust midpack which disappears as you tilt north. Yep, buried surface hoar on facets on a crust – nasty!

Photos:

Like skinning in a sandbox

CBAC2020-21 Observations

Zone: Northwest Mountains

Location: Hancock

Date of Observation: 11/30/2020

Name: Zach Guy

 

Subject: Like skinning in a sandbox

Aspect: North East, East, South West

Elevation: 9,600 – 12,400′

Avalanches:

None today.

Weather: Clear skies, mild temps, moderate westerly winds

Snowpack: We found good stability on steep terrain and noted plenty of weak layers on the snow surface for future problems. Several pits on NE aspects targeting persistent slab concerns were unreactive. In previously wind loaded areas(HS~90 cm), the basal facets show signs of being stronger, harder, and smaller grained now, and were also discontinous due to talus on the ground. In previously wind-scoured or shallow areas areas, the snowpack is quite weak (Fist hard, 1mm facets) but no slab. Snow surfaces consist of widespread .5mm near surface facets on northerly aspects, occasionally capped by a thin wind crust that produced clean shears and cracking. On southerly aspects, the surface is melt-freeze crusts of varying hardness with small grained facets above and/or below. It is hard to find a slope where there isn’t a PWL on the surface, except for the ones that have melted out to dirt. No signs of instability today on slopes up to 40 degrees.

Photos:

Groundhog’s day can be fun

CBAC2020-21 Observations

Zone: Northwest Mountains

Location: Upper Slate

Date of Observation: 11/29/2020

Name: Zach Guy

 

Subject: Groundhog’s day can be fun

Aspect: North, North East

Elevation: 9700-12,200′

Avalanches:

No recent avalanches. Spotted a few more small wind slabs from early last week.

Weather: Awesome.

Snowpack: Continuing the hunt for persistent slab feedback and not finding it. Went to a high, northerly bowl that we documented in early November as a potential problem slope with continuous weak layer coverage across the whole bowl. The 11/14 northwest wind event had clearly scoured back most of the slab, evidenced by reverse cornicing on the ridge, some veg poking out mid-bowl, and pole probing. A representative pit photo is attached, showing a shallow snowpack without the structure for a persistent slab. There were a few small lobes of potentially crossloaded slabs in the bowl that we easily avoided. We rode in steep terrain with no signs of instability.
In general, the snowpack here is weathering the decaying process much better than what I observed recently at Coney’s and Snodgrass: previous wind events and/or a deeper warmer snowpack is maintaining a supportive midpack so far. Near surface faceting is still occurring at all elevations. No surface hoar observed here.

Photos: