Observations

Date of Observation: 01/03/2021

Zone: Northwest Mountains
Location: Anthracite Region
Aspect: North East
Elevation: 9200

Avalanches: No evidence of recent Avalanche Activity
Weather: Calm cold and Humid up high
Snowpack: Skiing 30 degrees or less and still whumphing in certain areas of the snowpack on the uphill .. our lovely persistant slab issue I suspect.

Widespread faceting and surface hoar:Faceted snow refers to snow grains within the snowpack that have transformed into larger, angular grains. Facets have weak bonds with neighboring snow grains.

If you don’t care about the consequences , get beyond yourself and consider the danger you put others in when you need to be rescued.

Photos:

Date of Observation: 01/02/2021
Name: Evan Ross

Zone: Northwest Mountains
Location: Ruby Range
Aspect: South East, South
Elevation: 10,700-12,600

Weather: Low clouds in the morning obscured the range, as those moved out a high cloud shield moved over for the mid day, with clearing in the afternoon. Increased winds were the main weather factor. Moderate speeds from the NW.

Snowpack: Snow surfaces that looked beautiful the last few days, had gotten affected by the recent increase in winds. In our case slopes that had the best SE to E tilt held soft snow surfaces, while some more southerly slopes had been blown back to old soft crusts or soft wind texture. Probably just due to the way the winds flowed through and around the terrain. In this area, there wasn’t much for new wind loading and the windward side of the terrain didn’t really have much snow for transport.

Several hand pits on S to SE facing slopes at upper elevations revealed no current avalanche problem. Never really found enough slab on the 12/10 curst to try and get a result. While skiing through areas that appeared to be more wind-loaded previously, also produced no results. Snowpack heights were measured were surprisingly shallow in the 40 to 60cm range on average. I wouldn’t have much trust in the snowpack structure observed during the next loading event. Those hand pits were on slope angles in the low 30-degree range. So the curst facet sandwich would be collapsible under new load with enough weight. Didn’t observe the thickness of those buried crusts on steeper slopes or the snowpack structure on the deeper looking sections of the slope.

Date of Observation: 01/02/2021

Zone: Northwest Mountains
Location: First Bowl
Aspect: North, North East, East
Elevation: 11,350

Avalanches: 1 Skier Triggered D2 (red arrow). On our first lap (green arrow) we noticed no real signs of instability (no collapsing or cracking). Our stability tests were benign and our ski cuts produced no results. On our second lap while descending the ridge towards our intended chute, we noted that the snow seemed significantly more faceted and had a “trapdoor feel”. Skier 1 skied approx. 150ft into the chute before pulling out into the trees. Skier two followed and while making a final turn out of the chute to regroup with skier one, triggered the slide and was carried approx. 50ft downslope before skiing out of the path of the slab. The crown appeared to range between 1-2+ft and the debris ran approx. 700ft. The slab failed on October/November facets near or at the ground. There were no injuries. We are both incredibly thankful for the positive outcome.

Weather: Mix of sun & cloud. Light to moderate wind.
Snowpack: Unpredictable and frightening.
We also noticed surface hoar on every inch of terrain we traveled through, up to 5mm in size.

Photos:

Date of Observation: 01/02/2021
Name: Zach Guy

Zone: Northwest Mountains
Location: Poverty Gulch
Aspect: North, North East, East
Elevation: 9,600 – 12,200

Avalanches: One small natural wind slab that ran last night or this morning (E, NTL). No other fresh avalanches observed.
Weather: Moderate winds with light transport. Clouds increased through the day with a few snow flurries this afternoon.
Snowpack: Skinned, snowmobiled, stomped, and skied on dozens of previously untrammeled low angled slopes (mostly near/below treeline) without any obvious signs of instability today, in stark contrast to just about every tour in the past few weeks. It appears as if the snowpack in this deeper part of the zone is moving to a low likelihood, high consequence persistent slab problem. On a NE aspect near treeline, the slab is about 4 feet thick, mostly 1 finger hard. The 12/10 interface is 4F- to F+ 1.5 mm facets. Stability tests produced a mix of hard, propagating results (ECTP30) and propagation during isolation (ECTPV, which might have been user error).

Photos:

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Date of Observation: 01/01/2021

Zone: Northwest Mountains
Aspect: West
Elevation: BTL

Avalanches: See photos.

Photos:

Date of Observation: 01/01/2021
Name: Evan Ross

Zone: Northwest Mountains
Location: Slate River
Aspect: North East
Elevation: 9,000-11,400ft

Weather: The clouds came and then went again. Calm winds. Nothing notable.

Snowpack: The snowpack in this area is really variable given all the past avalanche activity it has seen throughout December. So it’s hard to make a call on the general stability. We traveled more aggressively on steep slopes where we had high confidence there wasn’t a current persistent slab avalanche problem due to past activity. We kept it real conservative where the conditions were unknown or undisturbed. The 12/10 interface remained the primary layer of concern. The more recent 12/22 layer of facets was observable, but we didn’t encounter any particular concerns there.

We didn’t get much for direct feedback, or obvious signs to instability. A few collapses and some shooting cracks all took some effort to produce. Confidence in the snowpack structure, where undisturbed, still remains low.

The upper 10 to 15cm’s of the snowpack is losing strength. SH was also widespread all the way to ridgeline. The slab had broken down the most at lower elevations below about 10,000ft.

Date of Observation: 12/31/2020
Name: Aaron Peterson

Zone: Northwest Mountains
Location: Washington Gulch
Aspect: South East
Elevation: 11,500

Avalanches: We did not observe any new slides.
Weather: Clear, calm, and gorgeous.
Snowpack: We traveled on south through east facing terrain to the east of Elkton and felt routine collapsing on and off the skin track. Most notably, our pit showed a relatively firm (1 finger plus, almost pencil hard) slab resting on 40cm of basal facets. Test results on this interface were hard to trigger (CT 22- resistant, and ECTX), however they propagated easily (PST 34/100 end). The slab was stubborn and sturdy, but still scary. As if to drive the point home, after demolishing our pit I stepped aside and onto a thinner patch of snow near a wind blown feature. This triggered a very large wumph across our snowfield. “Nearly pant altering” according to my partner. We were incredibly happy not to be on steeper terrain.

Photos:

Zone: Crested Butte Backcountry
Date: 1/1/2021
Name: Jack Caprio/ Ian Havlick

Happy New Year! Unfortunately, our snowpack didn’t stay in 2020. Check out the weekly recap to see how the recent storms shook things up.

Date of Observation: 12/31/2020
Name: Zach Guy

Zone: Northwest Mountains
Location: Mount Emmons
Aspect: North, North East, North West
Elevation: 9000’ to 12,200’

Avalanches: Remotely triggered a large (D2) persistent slab from about 350 feet away. The slab was about 3 feet thick and 300 feet wide, on a north aspect above treeline.
Handful of previously unreported natural persistent slabs to add to the list from the last cycle. D2 up Peeler basin (E, ATL) and several D2s in Wolverine and Redwell Basin (NW, NTL).
Weather: Partly cloudy midday with clear skies on either end. Light winds
Snowpack: Large, rumbling collapses on low angle terrain still the norm on almost every open slope or small clearing in trees. Collapses are getting a little more stubborn now; sometimes it was the first person breaking trail, sometimes the 2nd or 3rd in line, and sometimes it requires a hard stomp.
Snow surface is faceting. Below treeline slopes that have previously avalanched in mid-December had good stability today.

Photos:

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.

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