Date of Observation: 05/10/2023
Name: Zach Guy

Zone: Southeast Mountains
Route Description: Copper Creek and West Brush Creek areas, viewed from Whiterock

Observed avalanche activity: Yes
Avalanches: Numerous previously undocumented D2 to D3 wet slabs likely ran during our April 9 to April 13 wet cycle. I coded their failure dates during the peak of the cycle 4/10 – 4/11, although I suspect activity was distributed across a wider date range than that.

Date of Observation: 05/10/2023
Name: Zach Guy

Zone: Southeast Mountains
Route Description: Copper Creek area

Observed avalanche activity: Yes
Avalanches: Numerous previously undocumented D2 to D3 wet slabs likely ran during our April 9 to April 13 wet cycle. I coded their failure dates during the peak of the cycle 4/10 – 4/11, although I suspect activity was distributed across a wider date range than that.

Date of Observation: 05/12/2023
Name: Zach Guy

Zone: Northwest Mountains
Route Description: Mt. Axtell 4th Bowl

Observed avalanche activity: Yes
Avalanches: A recent-looking large wet slab in Evan’s Basin. I’m guessing it ran sometime in the past few days.
Weather: Partly cloudy skies. Light northeast winds.
Snowpack: Less than 1″ of new snow above 10k, with isolated drifts up to 5″ from northeasterly winds ATL. Marginal refreeze due to last night’s cloud cover and insulating new snow, but the snow surface remained supportive under skis with good corn-like skiing through 9:30 a.m on northeast aspects. No signs of instability this morning.

Date of Observation: 05/09/2023
Name: Zach Guy

Zone: Southeast Mountains
Route Description: Red Ridge to Queen Basin to Whiterock Mtn

Observed avalanche activity: Yes
Avalanches: Skier triggered and observed a few fresh natural wet loose avalanches on high, north-facing terrain up to D1.5 in size.
Numerous previously undocumented wet slabs from the April cycle, D2-D3. I’ll document those in a separate ob later this week.
Weather: Clear to few clouds, warm temps, light breeze.
Snowpack: Wet loose avalanches became reactive to ski cuts by mid day on ATL northerly terrain, where the top 6″ of dry powder was just now transitioning to wet snow. Elsewhere, the snow surface has matured through numerous melt-freeze cycles and wet loose avalanches appeared to be unreactive, even on steep terrain late in the day. The snow surface remained supportive to skis through 4 p.m. at all elevations except for a few spots near evergreen trees below treeline.

Date of Observation: 05/07/2023
Name: Chris Martin

Zone: Northwest Mountains
Route Description: Today we traveled up Purples SE ridge to the top of the S couloirs and descended the couloirs with careful evaluation of snow totals and slab cohesion, with techniques that mitigated our exposure.

Observed avalanche activity: No
Avalanches: Dry loose, slow running

Weather: Low visibility, Light-Moderate winds and blowing snow. Cold.

We decided after last weeks warmup to wait for weather stations to reveal the refreeze this weekend and the cold temps that persisted throughout yesterday and today gave us the confidence to push into the alpine for today. The refreeze remains minimal below 2′ down on South Aspects.

Snowpack: 6-8″ of wind blown snow on top of a MfCr. We observed minimal and shallow cracking that remained local to the tips of our skis. The new snow seems to be bonding quite well to the old crust.

We observed pockets of deeper wind transported snow, we did not encounter anywhere these totals were connective across an entire slope as a recipe for propagation.

While traveling we also noticed the warm up from last week in the snowpack. Specifically on South aspects the freeze penetrated about 2 feet down from the past freezing temps since the morning of 5/4 and snow was moist/wet below that.

Date of Observation: 04/30/2023
Name: Insta Gram

Zone: Northwest Mountains
Route Description: Viewed from Ruby Peak.

Observed avalanche activity: Yes
Avalanches: Large slab avalanche off Mt Owen, with debris to Green Lake. Appeared to be cornice triggered.

Date of Observation: 04/29/2023
Name: Turner Petersen

Zone: Northwest Mountains
Route Description: Sledded up wash gulch and skied Quigley Creek Bowl and then the east bowl on Baldy with Syd and Sam.

Observed avalanche activity: Yes
Avalanches: Still seeing isolated NE Wind Slabs. Second skier triggered a small pocket. Turned to slow loose wet toward bottom. Ran maybe 400’.
Weather: Sunny. Warm. Winds from the NW.
Snowpack:

Date of Observation: 04/28/2023
Name: Zach Guy

Zone: Northwest Mountains
Route Description: Upper Slate and Yule Pass areas. Traveled mostly on easterly and northerly aspects to 12,600′

Observed avalanche activity: Yes
Avalanches: On north-facing terrain ATL, I skier triggered a thin wind slab (~6″ x 8′) and a loose dry avalanche that both ran about 800′ (D1s).
Wednesday’s sunny weather after the storm spurred a wet shed cycle around the compass except for high northerlies. These were mostly wet loose, D1-1.5, and a handful of slabs up to D2. Not sure if they were moistening storm slabs or wet slabs; the debris looked fairly wet.
Weather: Clear, unseasonably cool temps. Moderate northwest winds were blowing the 1″ of new snow around with small plumes off of high peaks.
Snowpack: 1″ of new overnight and winds formed isolated, thin wind slabs ATL. These appeared to be bonding well on solar aspects; got one to pop on a crossloaded north facing slope. There’s up to 10″ or so of recent storm snow from the Tuesday night storm which hasn’t fully transitioned yet and could continue to produce more wet loose activity this weekend, especially to human triggers. At 1 p.m. while skinning up Yule Creek (~10k’, fairly flat terrain), we were getting widespread collapses on the dust layer, which was about 6″ to 8″ deep and saturated. Most collapses were a ski length or two wide, but some produced shooting cracks up to 30′ or 40′. This suggests there is potential for thin wet slabs this weekend as well, similar in character to the avalanches on Schuylkill Ridge shown below.

Date of Observation: 04/28/2023

Zone: Northwest Mountains
Route Description: Mt. Owen, north side ATL

Observed avalanche activity: Yes
Avalanches: Skier triggered a soft slab. See photo.

Date of Observation: 04/26/2023
Name: Turner Petersen

Zone: Southeast Mountains
Route Description: Skied the M face on Whetstone with Tom Rob and Dan.

Observed avalanche activity: Yes
Avalanches: We kicked the top cornice which produced a very isolated and small wind slab that entrained any available surface snow on a stout north crust. Ran 1000′.
Weather: Sunny. Winds from the NW.
Snowpack: 5′ of new snow on a firm glazed north crust.

Photos: