Date of Observation: 12/29/2022
Name: Zach Guy

Zone: Southeast Mountains
Route Description: Rec tour on Anthracite Mesa, traveling on various aspects to 10,800′

Observed avalanche activity: Yes
Avalanches: Large natural slab avalanche likely ran this morning on a southwest facing slope of Gothic, to the ground. Skier triggered a couple of thin soft slabs that failed within the storm snow on lightly cross-drifted southerly terrain. Had decent vis of the Lower Slate from Birthday Bowl on Skooks to Happy Chutes and only saw a handful of loose dry avalanches.
Weather: Very light snowfall. Light winds with occasional moderate gusts causing brief periods of blowing snow. Cold temps.
Snowpack: 35 to 40 cm of F to F+ snow down to our most recent facet (1mm) and crust/facet layers. This interface produced only minor cracking and non-propagating results in quick tests. No signs of buried surface hoar here. In lightly wind-drifted terrain exposed to down valley winds, we produced shooting cracks and triggered a couple of soft slabs breaking on precip particles within the storm snow, up to 25 cm thick or so. One was remotely triggered from 20 meters away.

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

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.

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.

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.

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.

Date of Observation: 12/24/2022
Name: Phill Ott

Zone: Northwest Mountains
Route Description: AMR

Observed avalanche activity: Yes
Avalanches: An old hard slab in the Playground. Likely ran during the extreme wind event.

Date of Observation: 12/25/2022
Name: Zach Guy, Sierra Bishop, and Jack Caprio

Zone: Southeast Mountains
Route Description: Mount Emmons to 11,300′. We targeted southerly facing terrain in Racoon Basin and northeasterly facing terrain in Climax/Happy Chutes area.

Observed avalanche activity: Yes
Avalanches: We skier-triggered a pair of avalanches in Climax Chutes that started as facet sluffs but propagated wider as soft slabs once they started moving, entraining the entire snowpack (about 30 cm) to the ground, D1 and D2 in size. This path ran naturally around 12/6, so the old persistent slab structure was gone. We were surprised to see how wide the slabs propagated given that there was only 3″ or 4″ of soft, wind drifted snow above the faceted bed surface.
Weather: Partly cloudy skies, light winds, no precip.
Snowpack: In short, the snowpack is weak and ripe for another cycle with the forecasted storm. The snowpack is exceptionally weak on bedsurfaces of slopes that ran in early December: 2mm chained facets. We already got evidence of how touchy this layer will be from the slabs that propagated fairly wide today under only a few inches of soft, wind blown snow (4F). On southerly aspects, we got propagating results on the crust facet layer (12/20 layer) buried by a few inches of soft, windblown snow. We got a couple of collapses and shooting cracks near valley bottom on southerly aspects where recent wind drifting formed thin, hard slabs over these layers. On northerly slopes below treeline that haven’t already avalanched, slabs have faceted out and are unreactive in tests (ECTN M). Depth hoar is 4-5mm in size below a fist to 4F hard faceted midpack (1mm).

Date of Observation: 12/25/2022
Name: Evan Ross

Zone: Northwest Mountains
Route Description: NW Mountains, various aspects, BTL/NTL

Observed avalanche activity: Yes
Avalanches: While jumping around on a ridge, I triggered an estimated D2 avalanche off the NE side of the ridge. This avalanche released in early December facets and above the November facets. This appeared to be an old/hard wind whale at the top of the slope that would have been formed earlier this month during more southwesterly wind events. The entire snowpack in the crown was in various forms of the faceting process, except for the most recent 4″ on top. Despite the faceted snowpack, it was still 1F to 1F+ hard through most of the crown. Just slightly downhill of the crown, the snowpack was mostly weak and shallow, with just a little 1F left in the mid-pack. This was represented in the avalanche flank, and in recent travels on similar terrain. I suspect this old wind whale released and then flushed to the ground through the weak snowpack below.

Snowpack: Over the last few days traveling mostly in wind sheltered below treeline areas, there hasn’t been anything notable to report.