Lower Kebler Pass

CBACCBAC Observations

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

Zone: Northwest Mountains
Route Description: Lower Kebler Pass. Variety of aspects.

Observed avalanche activity: Yes
Avalanches: Few small storm slabs.

Weather: Overcast. Light down-valley winds in the afternoon. Snowing S1 to S2

Snowpack: Quick tour, mostly targeting some NE slopes BTL in lower Elk Creek. Other than a few small storm slabs, nothing notable in the lower Elk Creek area or near the road on Kebler. Traveled on several small test slopes, and near-defined avalanche terrain with no obvious signs of instability.

ENE, 31-degree slope, BTL that does see wind-loading. HS 153. The recent storm interfaces were down about 15cm and 25cm. December 20th was down about 70cm. ECTP 3 on the lower storm interface. ECTN 24 on 12/20. The 12/20 interface was very thin and difficult to see in the pit wall, but still defined 1mm NSF on the card.

Photos:

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CB Town ENE

CBACCBAC 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.

Photos:

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Remote trigger below Gothic Road

CBACCBAC Observations

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:

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Large avalanches on Emmons

10webCBAC Observations

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.

Photos:

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RMBL Gothic Snow Study Plot 12.30.22

10webCBAC Observations

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.

Photos:

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AMR in between storms

10webCBAC Observations

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

Photos:

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Irwin Guides cat ski control work

CBACCBAC Observations

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:

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Quiet on the Elkton Front

CBACCBAC Observations

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:

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A quick RLG

CBACCBAC Observations

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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