Observations

Date of Observation: 03/05/2023
Name: Zach Guy

Zone: Southeast Mountains
Route Description: Southeast shoulder of Gothic to 11,500′, and east side of Snograss BTL.

Observed avalanche activity: Yes
Avalanches: Several natural D1-1.5 wind slab avalanches on Axtell, Whetstone, and the Shield (Redwell Basin). One in Redwell Basin that looked large (D2) from a distance.
Weather: Mostly cloudy skies north of town, partly cloudy south of town. Light winds below treeline except for some periods of strong gusts/blowing snow in valley bottom. Blowing snow continued for most of the day off of the high peaks, and near treeline was somewhere between the two.
Snowpack: Snow surfaces remained soft and relatively unaffected by winds below treeline on Snodgrass. In sheltered terrain, the snow surface was denser and creamier compared to yesterday, with no new slab formation. As we moved into more wind exposed near treeline terrain, surfaces were heavily wind affected, varying from eroded to the last crust or loaded into hard thin slabs. Fresh wind slabs on small terrain features ranged from 3″ to 16″ thick. Some produced cracking, some produced collapses, and others gave no feedback to stomps or ski cuts. I didn’t ski cut the larger looking slabs in a proper windloaded start zone because I don’t like messing with hard slabs.

Photos:

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Date of Observation: 03/05/2023
Name: Irwin Guides

Zone: Northwest Mountains
Route Description: Irwin Tenure

Observed avalanche activity: Yes
Avalanches: Candy’s SS-ASc-D1-I 8-10″ X 30′ X 200′ MFC E aspect NTL

Pre-E SS-AE-D1- I 8-10″ X 40′ X 150′ MFC E NTL

NC SS-ASc-D1-I. 6-8″ X 40′ X 150′ MFC SE NTL
Weather: From 2100-1100 the winds averaged in the mid 40’s from the SW with several gusts in the 60’s-70’s topping out at 87 last night.
Snowpack: A few wind slabs on E NTL reactive to ski cuts, some quality breaker wind board on W N/ATL, and some nice pow stashes in the safe places down low amongst the forest creatures.

6072

Date of Observation: 03/05/2023
Name: Ben Ammon

Zone: Southeast Mountains
Route Description: Coney’s

Observed avalanche activity: No
Avalanches:
Weather: Hella blowy.
Snowpack: 10,550′ NE 30* slope HS 295cm
ECTN 24 down 35cm
ECTN 27 down 50cm
ECTN 30 down 80cm
second ECT produced same results
no propagation or reactivity down to 110cm

6071

Date of Observation: 03/04/2023
Name: Danny H

Zone: Southeast Mountains
Route Description: Travelled up to the Snodgrass saddle and then up towards Gothic through an southeast facing couloir.

Observed avalanche activity: Yes
Avalanches: Remnant avalanche that came through the spork couloir down Gothic probably from the wind loading last week. Also saw evidence of cracking with a 4-inch thick propagating crack that gave on the old wind crust from last week.
Weather: Calm and overcast until around 4pm when ridgeline winds began ripping.
Snowpack: Dug a test pit to assess the faceted layer about 2 feet down. The facets were overlaid by a 4cm thick melt-freeze crust most likely from the period before this last number of storms and we could not activate the weak layer with ECTX results.

6070

Date of Observation: 03/04/2023

Zone: Southeast Mountains
Route Description: Carbon Peak

Observed avalanche activity: Yes
Avalanches: Fresh wind slab in the past 24 to 48 hours off of east face of Carbon
Weather:
Snowpack: Pretty good collapse at 10,000 ft along a broad ridge, snowdepth was 200 cm at that location.

Photos:

6069

Date of Observation: 03/04/2023
Name: Zach Guy

Zone: Northwest Mountains
Route Description: Traveled on various aspects of Mt. Owen and Mt. Afley to 13,000′, mostly N/ATL.

Observed avalanche activity: Yes
Avalanches: A notable amount of avalanches in the new snow ran overnight, D1 to 1.5, with a couple long running slides approaching D2 in size. These appeared to be a combination of loose snow avalanches and soft slabs of wind drifted snow, on all aspects above treeline.
Conditions were relatively quiet today, I was able to ski trigger a small wind drift and get some shallow sluffs.
Weather: Thin overcast with enough solar to moisten some sunny slopes. Light winds most of the day started ramping up around 2 p.m. At 3p.m. we were on top of Afley and immersed in intense blowing snow and whiteout conditions during strong gusts.
Snowpack: 24-hour storm totals ranged from 10″ near treeline to 16″ in sheltered terrain above treeline! Low density with signs of wind drifting in the more exposed terrain. I produced some localized cracking in those drifts, up to 18″ thick or so. We observed one collapse on a west aspect near treeline of Afley Peak, estimated about 18″ deep on some older facet/crust layers.
Fetches were blown dry at ridgetop from last night’s winds, but there’s still plenty of loose snow available for transport (10-15″) further downslope in alpine fetches or in less exposed near treeline terrain for tomorrow’s winds to work with.

Photos:

6068

Date of Observation: 03/04/2023
Name: Ben A

Zone: Southeast Mountains
Route Description: Snodgrass East and North

Observed avalanche activity: No
Weather: Overcast most of the day with occasional moments of greenhousing, and Souths were warming.
Snowpack: 10,000′ E – HS 195cm
CTH down 25cm and 40cm
ECTN24 down 25cm, ECTN26 down 40cm
ECTP down 90cm on bonus taps after removing the ECTN results

6067

Date of Observation: 03/03/2023
Name: Zach Guy

Zone: Southeast Mountains
Route Description: Traveled on the southern side of Mt. Crested Butte, on various aspects up to 10,500′

Observed avalanche activity: No
Avalanches: Shallow sluffing in very steep terrain
Weather: An inch of new snow. Calm winds below treeline.
Snowpack: Snowpack tests on various aspects were unreactive; the snowpack felt generally safe. The upper snowpack facet layers are weaker and more developed here than in deeper areas, but I couldn’t find enough of a slab above those layers to be an issue. The most concerning structure I found was on a lightly cross drifted NE facing slope, with a 45 cm soft slab (4F) over F+, 1mm facets. It produced moderate, non-propagating results. Stacks of crusts or faceted crusts add strength to the upper 20 cm of the snowpack on the southern half of the compass. Deeper layers were unreactive; the midpack is generally faceted out.

Photos:

6065

The weekly summary is here. A series of storms brought over 2 feet of snow to the valley and a natural avalanche cycle that ran after the extreme winds on Monday 2/27.

Weekly Summary February 24 – March 2, 2023 COMPRESSED

Date of Observation: 03/02/2023
Name: Evan Ross

Zone: Southeast Mountains
Route Description: Brush Creek. 9,000ft to 11,600ft. NE-E.

Observed avalanche activity: Yes
Avalanches: The most recent-looking avalanche failed in the last couple of days. 11,800ft, NE slope, some cornice chunks popped a slab avalanche that become large in size. Best guess is that this slab broke within the recent storm snow around 30 to 45cm deep below a wind-loaded ridgeline.

A couple of other large avalanches failed on an East facing slope near the Union Chutes and the south face of Teo. These each had around 25 to 30cm of snow on the debris so I’d estimate they ran during the extreme wind event around 2/22.

Weather: The clear sky became partly cloudy in the afternoon. I saw a couple of snow plumes off the high peaks before mid-day, otherwise nothing notable and calm winds while I was out.

Snowpack: Targeted the late January to February portion of the snowpack. In some areas around 9,300ft, the interface that was buried in early February still consisted of well-developed near-surface facets. However, on an east-facing slope at 9,300ft, I only got ECTN results and no results on test slopes. HS in these areas was 140cm or less and the 20 to 30cm of snow on top of that interface was perhaps just not enough of a slab.

Further up Brush Creek at 10,300ft the HS had climbed to 185cm and the same interface was buried by about 50cm’s of snow. The interface was notably less weak and didn’t produce in ECT or CT tests.

I spend some time trying to find the goldilocks slope between those to data points that would produce an unstable result or show signs of instability but never found it. There were some other suspect areas that would have been nice to look at.

Great skiing on NE-facing slopes, while East-facing slopes were developing a new crust. Steep south-facing slopes ATL had a few roller balls and loose snow avalanches.

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