Date of Observation: 04/06/2023
Name: Zach Guy

Zone: Northwest Mountains
Route Description: Traveled on various aspects on Mineral Point and Cascade to 12,500′.

Observed avalanche activity: Yes
Avalanches: Numerous small dry loose avalanches ran today on northerly terrain, and we ski-triggered more of the same (D1). A couple small wet loose ran on an E/SE aspect BTL of Cascade (D1). Several large cornice falls failed sometime since the storm ended, past 48 hours (D2). Several D1 to D2 wind slabs ran during the storm, some related to cornice fall. See photos and details below, the storm-related avalanches are coded in a separate ob.
Weather: Clear skies, calm winds, cold temps near zero this morning rising to 20F at 12k midday.
Snowpack: There’s about a foot of fairly dense storm snow near and above treeline in the Ruby Range with signs of previous drifting. The snow appears to be bonding well to the storm interface, based on targeted feedback from numerous steep test features. We got some shallow cracking a few inches deep from the most recent drifting. The snow stayed dry on northerlies, got a little moist on easterlies, and just the surface got wet on southerlies. The dust is resurfacing on low-elevation southerlies near town.

Date of Observation: 04/05/2023
Name: Ben Pritchett

Zone: Southeast Mountains
Route Description: Cement Creek to Hunter Creek to Star Pass

Observed avalanche activity: Yes
Avalanches: One small cornice-triggered D1 slab in the Timbered Hill Chutes, which looked like it ran Sunday at the end of the last warm-up. The cornice chunks and debris gouged like the snow was wet a the time.
Weather: Broken skies, flat light, cold temperatures, and nearly calm westerly winds.
Snowpack: Below treeline, the snowpack on all aspects has undergone 4 melt-freeze cycles in the last month (2x in early March, the beginning of the March 20 storm, and late March warm-up). These crusts had water percolate between them repeatedly, making for a very stout upper snowpack structure now. Even at the upper elevations of this elevation band on shady slopes where thin crusts formed, we found no weak layers of concern.

Date of Observation: 04/05/2023
Name: Zach Guy

Zone: Northwest Mountains
Route Description: Mt. Axtell, traveled mostly on N to E aspects to 11,900′.

Observed avalanche activity: Yes
Avalanches: Skier triggered and observed a few natural loose avalanches, small in size (D1). Ski cut a small wind slab about 6′ wide, 12″ deep on a crossdrifted north facing slope NTL (D1). There was a thin natural windslab below ridgeline in 4th Bowl, about 4″ deep.
Weather: Partly to mostly cloudy with a few afternoon flurries (S-1). Light winds, no transport.
Snowpack: About 4″ to 5″ of storm snow, delineated by a prominent dust layer near the bottom of the storm. I found a few drifts up to a foot thick in typical locations; ski cuts and stomps were unproductive except one small pocket. It seems most of the wind transport here happened early in the storm before there was much snow available for transport. The last few inches of snow were relatively unaffected by wind and also concealed some of the previous drifting textures.

Date of Observation: 04/04/2023
Name: Eric Murrow

Zone: Northwest Mountains
Route Description: Kebler Pass to Scarp Ridge on snowmobile and ski tour around the Anthracites.

Observed avalanche activity: Yes
Avalanches: Visibility was poor much of the day, but I could see storm snow debris on a drifted easterly slope near treeline at the top of the Playground in the Anthracites. This feature has a large fetch for gathering snow.
Weather: Mostly cloudy skies with consistent light snow with a few short periods of S2. Storm total of 6 inches around 4pm at 11,000 feet. Moderate wind speeds on near treeline ridgeline.  It is hard to miss the dust at the base of the storm snow, yuck.
Snowpack: Crusts at the old snow surface, just over 11,000 feet, were 3-4cm on southeast slopes, 2cm on east terrain, and thinned away as you move into northeast aspects. North-facing slopes in this area remain fully dry and provided nice turns. I was able to produce a few shooting cracks on drifted near treeline features, but fetches were relatively small so wind slab formation was only a few inches thick.

Date of Observation: 04/02/2023
Name: Zach Guy

Zone: Northwest Mountains
Route Description: Morning tour on Mt. Emmons, traveling on southerly and northerly aspects to 12,000′

Observed avalanche activity: Yes
Avalanches: Several notable large avalanches that ran sometime since Evan was on Mt. Emmons yesterday morning. These likely ran during Saturday afternoon’s peak warming, or the cornice falls could have happened overnight. Plus a few older wind slabs that likely ran during Friday’s storm.
-A second cornice fall in Redwell Basin, extending dirty debris further than the slide in the same area that Evan documented yesterday, and prying out a couple of slabs in the upper snowpack, ~D2.5 to D3 in size.
-Several wide D2 to D2.5 storm slabs that ran on the southwest side of Schuylkill Ridge to valley floor in OBJ, snapping several trees.
-A large wind slab in Peeler Basin that was triggered by cornice fall, D2.
Weather: Strong winds above treeline and moderate winds below treeline were helping to keep snow surfaces cool today. Winds appeared to be sublimating the drifting snow  more than loading. Few clouds. Spring temps.
Snowpack: Skied steep, north-facing terrain with no signs of instability. On solar aspects, crusts started to soften around 11 or noon. I didn’t see any active rollerballs or wet loose activity by the time we left at 1 p.m. I stomped around above a wind-loaded east-facing slope midday and couldn’t produce any signs of instability.

Date of Observation: 04/02/2023
Name: Evan Ross

Zone: Southeast Mountains
Route Description: SE Mountain FX area

Observed avalanche activity: Yes
Avalanches: 4 cornice avalanches that failed since Friday. 2 above Copper Creek on a SE aspect at 12,000ft. Another 2 in the Hidden Lake Bowl of Mt Whetstone on a northerly facing slope at 12,200ft. The Hidden Lake Bowl cornices may be repeat offenders similar to those that keep falling into Redwell.

Date of Observation: 04/02/2023
Name: Evan Ross

Zone: Northwest Mountains
Route Description: Slate River to Cascade

Observed avalanche activity: Yes
Avalanches: The natural loose wet avalanche activity has remained fairly minimal, with fewer small loose wet avalanches and more roller balls.

Got a closer look at the natural slab avalanche, that ran late Saturday afternoon, above the Slate River Rd. This avalanche ran on a SW aspect at 10,800ft. The best guess is that this was a natural storm slab avalanche that failed during the rapid warming event that occurred on Saturday. The slab looked to have run on the old snow interface. Near the avalanche debris, the top 10 cm of the snowpack had become wet and the remaining storm snow below was dry.

Weather: Partly Cloudy, Light to moderate winds with blowing snow off the high peaks.

Snowpack: The wind was penetrating to valley level and helping keep snow surfaces somewhat cool. Loose wet avalanches appeared to be more problematic yesterday. The wind in the alpine looked like it was doing more eroding than actual wind-loading.

Date of Observation: 04/01/2023

Zone: Northwest Mountains
Route Description: Slate River

Observed avalanche activity: Yes
Avalanches: This avalanche ran late on 4/1. Natural or a remote trigger.

Date of Observation: 04/01/2023
Name: Evan Ross

Zone: Southeast Mountains
Route Description: Mt Emmons. Redwell Tour.

Observed avalanche activity: Yes
Avalanches: A wide propagating slab on an easterly aspect into Redwell Basin. 11,600ft. D2. Avalanche debris looked soft so I’d estimate it ran yesterday during the storm.

A fresh cornice fell in redwell basin, probably ran this morning or at the end of the storm. D2.

A fresh cornice fell in the Climax Chutes, probably ran this morning or at the end of the storm. D1.5

Roller balls and some small loose wet avalanches around the solar half of the compass.

Weather: Clear sky, rising temps. Calm winds down low and light winds in the alpine.

Snowpack: At 10,800ft on the South side of Mt Emmons the recent HST was 35cm. We climbed the south side of Mt Emmons while the snow was just warming, then skied dry snow of the West and north sides. By the time we hit OBJ and changed both aspects and elevation the snow surface was wet. This tour was for good snow and avoided the avalanche problems.