Date of Observation: 01/01/2023
Name: Zach Guy

Zone: Southeast Mountains
Route Description: Snowmobiled Cement Creek to the base of Hunter Hill.

Observed avalanche activity: Yes
Avalanches: Widespread and ongoing natural and remotely triggered persistent slab activity that appeared to start last night and go through today, localized to Upper Cement Creek (east of Deadman’s Trailhead). In that upper basin, almost every single steep slope that we rode near remotely avalanched if it hadn’t already gone naturally. Dozens of small creek beds released, and we triggered about half a dozen larger slopes just riding in the flats. More natural avalanches than I could count. Crowns were generally about 2 feet thick, and most appeared to fail on the mid-December facet layer. Small terrain features produced D1-1.5s, and larger terrain produced D2s. Avalanches were occurring on all aspects, which are generally E, SE, W, and NW below treeline in this basin. Couldn’t see the alpine.
Weather: Light snowfall with a few moderate pulses. Calm winds below treeline.
Snowpack: This might have been one of the most widespread, touchy persistent slab days I’ve ever experienced in my career; truly fascinating and blatantly dangerous. Human triggering felt almost certain. Riding into open slopes consistently produced rumbling collapses with trees shaking hundreds of yards away, shooting cracks opening on moderate angled slopes, and almost everything steeper than 35 degrees would slide. Collapses occurred on mid-December facets and depth hoar, which are now in the bottom 3rd of the snowpack below a 60 to 90 cm slab. Tests produced sudden collapses on isolation in the depth hoar (ECTPV). Near the trailhead, I watched a small dog step off the road and trigger a shooting crack across a slope. In Lower Cement, slabs are thinner (~30 cm), and better anchored by ground roughness, sagebrush, etc, thus the danger was less threatening.

Date of Observation: 01/01/2023
Name: Zach Guy

Zone: Northwest Mountains
Route Description: Ohio Pass.

Observed avalanche activity: Yes
Avalanches: Several large avalanches covered Ohio Pass Road. One of these ran yesterday reported by a group of snowmobilers. Unclear whether it was triggered or natural. The other two ran this morning.

Date of Observation: 01/01/2023
Name: Zach Guy

Zone: Southeast Mountains
Route Description: Mt. CB

Observed avalanche activity: Yes
Avalanches: Brief visibility this morning of large to very large avalanches on Whetstone and Gothic.

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.

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.

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:

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:

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.

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.