Observations

Date of Observation: 12/29/2022
Name: Billy Barr

Zone: Southeast Mountains
Route Description: Gothic Townsite

Observed avalanche activity: No
Weather: Light snow during the day with 4″ new and 0.24 SWE, then snow last night ending by midnight with 3″ more and water 0.21″ so the 24 hour total was 7″ new and 0.45″ of water content. It remained cloudy and calm while warming to freezing and then cooling to 11F overnight. Currently overcast and not snowing with a light westerly wind and 13º with a light wind. Snowpack is at 37″. billy

5806

Date of Observation: 12/28/2022
Name: Jack Caprio

Zone: Southeast Mountains
Route Description: Snodgrass. Northeast side

Observed avalanche activity: Yes
Avalanches: We skier triggered plenty of loose dry avalanches in the new snow. Some of the loose dry avalanches entrained into old snow.

We intentionally skier triggered 3 soft slab avalanches failing deeper into the snowpack. In both 1st and 2nd bowl, we triggered soft slab avalanches breaking below the new/ old snow interface.

The loose dry avalanches failed on the 12/27 interface, where as the slab avalanches broke 6-8” below the 12/27 interface (see photos).

We remotely triggered a soft slab avalanche off the gothic road-cut on our way out (<D1)
Weather: S-1 snowfall all day. Warm temps. Overcast skies.
Snowpack: 6-9” of new, high density snow. On northeast aspects below treeline, the new snow fell on top of very weak snow surfaces.

Photos:

5805

Date of Observation: 12/28/2022

Zone: Northwest Mountains
Route Description: Red Coon glades

Observed avalanche activity: No
Avalanches: No signs of instability were observed.
Weather: Warm. Estimated air temp was 40F
Light snow most of the day. S-1
No wind
Snowpack: Storm snow was 7”. HS was a meter
The surface conditions were stellar s with no wind effect. No wind texture at all.
The old snow new interface had an old sun crust but the new seemed to bond well

5804

Date of Observation: 12/28/2022
Name: Eric Murrow Zach Kinler

Zone: Northwest Mountains
Route Description: Kebler Pass to Anthracites standard skin track.

Observed avalanche activity: Yes
Avalanches: No natural avalanches. Observed two small human-triggered avalanches by other parties on east and northeast aspects. We remotely triggered 3 separate avalanches, D1 and D1.5, on northeast, southeast, and south aspects. All of the avalanches we triggered failed on Surface Hoar immediately beneath the storm snow.
Weather: Mostly cloudy skies with light snowfall throughout the day. The height of storm snow at 2pm was about 13 inches with 1.3″ of water. Winds remained light at the ridgetop with no drifting observed.
Snowpack: In each place we looked, northeast through east through southeast through south near and below treeline, we found 6 – 9 mm surface hoar beneath the storm snow. The collapses that triggered the avalanches mentioned were quiet and hard to hear or notice. One of the avalanches on a southeast aspect was triggered from 150 feet away. Whether the weak layer was buried surface hoar, the 12/20 facets, or within the storm snow, it seemed likely to trigger a small avalanche in the surface snow (some long slopes could have approached D2 size). On southerly slopes, a melt-freeze crust formed in the past few days that have the potential to collapse and produce avalanches with more snowfall this weekend. Below the crusts, the snowpack was only lightly faceted but remains soft and collapsable. The biggest takeaway was buried surface hoar, in open areas, beneath the recent storm snow on most aspects near and below treeline in this area.

Photos:

5803

Date of Observation: 12/28/2022
Name: Zach Guy

Zone: Southeast Mountains
Route Description: Morning tour in the East River area near Gothic road, around 9500’ on easterly aspects

Observed avalanche activity: Yes
Avalanches: I ski triggered and saw a handful of natural loose dry avalanches this morning that entrained old snow, D1 in size. Later in the morning, I skier triggered a few soft slab avalanches with minor propagation, that failed on the 12/20 facet layer, about 10” deep.
Weather: Snowfall rates tapered to very light by mid morning. Calm winds.
Snowpack: About 7” to 9” of new snow, started out incohesive and sluffy and settled to slabbier as the day warmed up. By late morning, I started getting shooting cracks up to 20’ and triggered a few small soft slabs on test slopes, breaking on our most recent facet layer. More notable, I got several rumbling collapses in flatter terrain that failed on the depth hoar at the ground, about 3 feet deep. All of the steep pitches that I approached had either shed that more dangerous structure previously, or winds eroded it last week.

Photos:

5802

Date of Observation: 12/28/2022
Name: billy barr

Zone: Southeast Mountains
Route Description: Gothic

Weather: Obscured with moderate to heavy snow since starting 12 hours ago with 9½” new and water content 0.82″ and no wind (hooray for that). It stayed very warm last night with the morning low the current 27F after a high yesterday of 41F. Currently snowing moderately with no wind and no visibility. Snowpack is at winters deepest of 31½”. There was a bit of crusting on southern slopes yesterday but now buried.

5801

Date of Observation: 12/27/2022
Name: Zach Kinler and Evan Ross

Zone: Southeast Mountains
Route Description: West Brush Creek

Observed avalanche activity: No
Avalanches: A couple of very small facet sluffs on steep, sheltered East aspects.
Weather: Cool and moist in the valley to start the day with clouds thickening. Nice and warm once we were out of the inversion, light southerly winds in open areas.
Snowpack: We traveled on east and southeast slopes from 9,800′-11,400′. The upper half of the snowpack in this zone is very weak. Southeast slopes had an HS of 50cm. Surfaces were a 3cm crust followed by 10cm of moist rounds. Below that was a thin crust with facets above and below. The bottom 30cm were moist grains to the ground. Moving into east, HS was 60cm, the surface crust was not present just 30cm of fist hard large-grain facets above a 4F faceting slab. 3-4 mm Surface Hoar was present from valley bottom to over 11,000ft on east aspects.

5800

Date of Observation: 12/27/2022
Name: Zach Guy

Zone: Southeast Mountains
Route Description: PM Snodgrass tour, poking into 1st Bowl, 2nd Bowl, and 3rd Bowl

Observed avalanche activity: Yes
Avalanches: Skier triggered several small facet sluffs that entrained weak snow to the ground. These were in start zones that ran earlier this month.
Weather: Light snowfall started around 3:30 pm.
Snowpack: The snow surface was widespread small grained near surface facets on all aspects. Near the trailhead I found surface hoar up to 4-5mm, but I did not see it anywhere else along my tour, including the main start zones near ridgetop. All three of the start zones that I looked at had avalanched previously and held a very shallow snowpack with very weak facets (2mm) that sluffed easily. The snowpack elsewhere is faceted throughout, weak layer size and strength correlated to snow depth, ranging from 1-2mm. Southerlies held one or two collapsible crusts up to a few cm thick with facets above and below. Wind exposed terrain had a mix of wind crusts and thin hard wind slab over these layers.

Photos:

5799

Date of Observation: 12/27/2022
Name: Tom Schaefer

Zone: Northwest Mountains
Route Description: Snow safety mitigation Irwin tenure E aspect 11’600′ 37 deg slope angle.

Observed avalanche activity: Yes
Avalanches: #1 HS-AB-R2-D2-O. 40 cm’s X 55m X 60m
#2 HS-ASu-R2-D2-O. 40 cm’s X 40m X 60m
Both failed on a thin layer of 1mm FC above a thin MFC 30 cm’s above the ground.
Avalanche #2 was triggered unintentionally from the flank mid slope as we tiptoed onto it after a cover shot was placed higher on the slab.

Weather: OVC, 32 deg. SW 20-30 mph.

Snowpack: HS 30-80 cm’s variable snow pack ranging from wind stiffened to pockets of weak facets and sun crusts.

Photos:

5798

Date of Observation: 12/26/2022
Name: Evan Ross

Zone: Northwest Mountains
Route Description: Primarily SE to SW between 10,000ft and 11,000ft.

Observed avalanche activity: No

Weather: Few clouds in the morning becoming overcast in the afternoon. Calm wind.

Snowpack: Targeted three test profiles, specifically looking at the upper snowpack, on SE, S and SW. The two most prominent interfaces are in the upper 15 to 35cm’s of the snowpack, depending on location, (12/11 and 12/20). On the south and southeast, the grains at those interfaces are around 1mm in size and notably rounding. The rest of the mid and upper snowpack at these locations had little change in hardness and looked generally strong, at least compared to current big-picture conditions. In the SW profile, the HS was notably less, and those two interfaces had slightly smaller grains, but they remained faceted and were not rounding.

Aspect: SE. Elev: 11,250. Slope: 30. HS: 103. 12/20 interface down 15cm and 12/11 interface down 25cm. 1mm rounding faceted particles at both interfaces. Some necking between grains. CTM, ECTN 15.

Aspect: S. Elev: 10,850. Slope: 30. HS: 128. Cross-loaded slope. The two interfaces were down 25cm and 30cm. Similar grains to the SE aspect. ECT PC 17, interestingly two additional loading steps were required to get the fracture to cross the column. Followed by an ECTN with no propagation across the column.

Aspect: SW. Elev: 10,800. Slope: 33. HS: 70cm. The two upper interfaces were down 15cm and 20cm. The most notable had a 1cm soft crust capping 1mm facets. Given the shallower snowpack compared to the other two locations, this snowpack was noticeably weaker and will handle less loading once a new slab develops.

Photos:

5796