Observations

Date of Observation: 12/31/2022
Name: Evan Ross

Zone: Southeast Mountains
Route Description: Near town. 9,100ft. ENE.

Observed avalanche activity: No

Weather: Overcast. Calm winds. Lull in the snow this morning, otherwise snowing most of the day.

Snowpack: Skinning was horrible in the upside-down upper snowpack. Didn’t travel through much terrain, but no notable obvious signs to instability. Targeted one quick profile on a 36-degree, 90cm, ENE slope at about 9,100ft. The thick portion of the storm slab was only about 3cm, with soft snow above and below. Shovel tilts easily produced results in the upper 15cm of the snowpack. The December facets are still large and prominent, but the snowpack is still generally soft and soft. A small storm slab in this terrain would have easily gouged and entrained the weak snowpack if the slope was steep enough.

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Date of Observation: 12/31/2022
Name: Eric Murrow

Zone: Southeast Mountains
Route Description: Nordic skied first mile of Gothic Road. Walked few hundred feet below the road to get above a steep northeast-facing slope.

Observed avalanche activity: Yes
Avalanches: Remote triggered an avalanche on a northeast-facing slope. Did not hear the collapse, but saw the powder cloud form out the bottom. It broke in three places and as it ran entrained much of the generally weak snowpack.
Weather: S2 snowfall from 1130 to1. Winds light with little evidence of recent blowing snow on roadway.
Snowpack:

Photos:

5815

Date of Observation: 12/31/2022
Name: Zach Guy

Zone: Southeast Mountains
Route Description: Rec tour on Mt Emmons, mostly on SE aspects BTL

Observed avalanche activity: Yes
Avalanches: A pair of fresh large natural avalanches in Racoon Basin. There were small trees in the debris, and I’m guessing they broke on the mid December later based on crown size. One smaller slab that broke in the new snow on a drifted feature.
Weather: Moderate snowfall rates all morning with a few heavy pulses. Light to moderate snow transport at ridgetop
Snowpack: Top heavy 8” of storm snow produced clean shears. Moderate propagating test results below the mid December facet crust layer, about 70 cm deep. Got a few muffled collapses on that layer but still relatively quiet where we were (on low angle terrain).  Slab is consolidating and getting noticeably denser compared to similar slopes yesterday.

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5814

Date of Observation: 12/30/2022
Name: Sophia Todorov

Zone: Southeast Mountains
Route Description: RMBL Snow Study Plot in parking lot in front of Dining Hall

Observed avalanche activity: No

Weather: Light snow, overcast, calm, about 15 degrees F

Snowpack: Easy to delineate 3 distinct layers in the snowpack. Top half (34cm) is fresh precipitation from current storm cycle. Middle layer is faceted and very weak (19cm thickness). However, we did not observe any collapse or propagation during an extended column test. ECTX. no result from an extended column test.

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5813

Date of Observation: 12/30/2022
Name: Mark Robbins

Zone: Northwest Mountains
Route Description: AMR

Observed avalanche activity: Yes
Avalanches: Small skier triggered storm slab at the convexity lower skiers right big chute where it often slides

Snowpack: Surprisingly quiet except for the storm slab release previously mentioned. Other ski cuts and stomping around on little wind lips yielded no results

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5812

Date of Observation: 12/29/2022
Name: Irwin Guides

Zone: Northwest Mountains
Route Description: Irwin Guides tenure.

Observed avalanche activity: Yes
Avalanches: We triggered several avalanche events with explosives in the process of cleaning up Persistent Slab problems in our easterly zone. Other than that, stability was generally good.

SS-AE-R1-D1-I PP (20cm x 15m x 80m)
HS-AE-R2-D2-I PP (50cm x 20m x 175m)
Weather:
Snowpack:

5810

The weekly summary is here. A 20+ inch storm of heavier-than-average snow on Wednesday 12/27 brought winter back to the valley and High avalanche danger. More snow is on the way for this weekend and the avalanche danger will rise accordingly.

Weekly Summary December 23-29 updated-compressed

Date of Observation: 12/29/2022
Name: Eric Murrow

Zone: Northwest Mountains
Route Description: Washington Gulch to Elkton Knob area.

Observed avalanche activity: Yes
Avalanches: Visibility was obscured all day, but I did get a view of two natural avalanches off Gothic Mountain. One was reported In Zach ob earlier today. The other was on a near treeline southwest-facing slope; it appeared to break only in the recent storm snow based on depth, D1.5 best guess.
Weather: Mostly cloudy skies, with very light but consistent snowfall through 3pm. Total storm depth through 3pm at 11,000 feet near Elkton was about 22 inches. Westerly winds blew at light speeds with moderate gusts throughout the day. Some snow transport near treeline and modest loading above treeline.
Snowpack: I traveled mostly through near treeline terrain. I experienced no signs of instability underfoot other than some ski-length cracks on drifted easterly terrain. I did not observe any buried surface hoar. The new snow remains dense but relatively soft. In this near treeline terrain, the 12/20 facet layer is capped by a thin windboard from last week’s wind event. A test profile produced no propagating results (see photo). Basal depth hoar remains in the Fist plus or 4 finger minus hardness range. This storm appeared to not quite be enough load to cause widespread natural activity for the ‘snowbelt’ region but, as mentioned above, visibility was obscured.

Photos:

5809

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

Zone: Southeast Mountains
Route Description: Standard Red Lady skinner to the glades.

Observed avalanche activity: Yes
Avalanches: Saw 2 naturals on a SE aspect around 11,200′ that failed late yesterday with several inches of snow in the bed surfaces. Both released on surface/hoar resting on a thin melt-freeze crust. D1-D1.5 in size. Crowns were around 10″.
Weather: Cloudy and cold, westerly winds were light in lower elevation sheltered terrain but moderate near and above treeline.
Snowpack: Fairly quiet snowpack when departing the skin track and on the descent. The recent collapses have been very quiet so possibly didn’t hear some of them. There was around 12″ of recent snowfall on the 12/27 interface. On south and southeast aspects this layer was surface hoar resting on a 2-3 cm crust. SH did not look as large or well-developed as other slopes I have seen. Looks to be decomposing a bit and getting entrained in the slab. It still produced easy hand sheers and is weak. Stomping on a few east and southeast slopes from the ridge did not produce any results.

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5808

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.

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