Date of Observation: 03/25/2023
Name: Evan Ross

Zone: Southeast Mountains
Route Description: Brush Creek out to Teo

Observed avalanche activity: Yes
Avalanches: East, 9,700ft. Remotely triggered a small avalanche from a couple of hundred feet away. This was a wind-loaded terrain feature and a lot of the feather isn’t steep enough to avalanche. The crown is estimated to be 60 to 70cm thick. I didn’t get to check the crown.

East, 10,100ft. Remotely triggered a D1.5 from 15 feet away. The avalanche propagated above and into steeper terrain. The slab was 65cm thick and around 280 feet across. The weak layer was the 3/20 crust collapsing into the 3/15 crust. The average slope angle of the bed surface was 40+ degrees.

Weather: Obscured with poor visibility. Light to moderate winds at lower elevations. I wore 2 down coats and a shell, must be getting soft.

Snowpack: Hunting some obvious signs of instability and they were somewhat hard to find. In general, the faceted crusts in the upper snowpack were similar to those in the NW Mountain forecast area. On some occasions, I got results with last week’s storm snow failing on the 3/20 crust, and in others, the 3/20 crust was collapsing into the 3/15 crust. I only got two notable collapses while traveling through the terrain. HST since yesterday was 4″. Visibility was poor, but what below treeline terrain I could see didn’t have a notable natural avalanche cycle last week.

Date of Observation: 03/25/2023
Name: Evan Ross

Zone: Southeast Mountains
Route Description: Gothic

Weather: Moderate to heavy snow after dark stopping around midnight with 6″ new and water 0.54″. The snowpack is at 95″ deep, just below the winter’s deepest of 97″ but the past 4 days have been the deepest snowpack on record for these dates. A steady 4-8 mph west wind with gusting to 15 as temperature slowly drops. After a high yesterday of 32 it is currently the days low of 3 with a cloudy sky (now and for forever it seems).

Date of Observation: 03/24/2023
Name: Evan Ross

Zone: Northwest Mountains
Route Description: Slate River. Variety of aspects. Mostly stayed within 500 hundred feet of the valley floor.

Observed avalanche activity: Yes
Avalanches: Many of the avalanches in the Slate and upper Slate have already been documented. I targeted specifics on those weak layers and that info is below. Avalanches on easterly aspects had the largest propagation and the most number of avalanches. However Northerly and westerly aspects had their share. The crowns in the alpine appear to be drifted back over or not visible with the recent weather.

I remotely triggered one large slab avalanche from a few hundred feet away, while traveling on a low-angled slope below. The avalanche ran on a west-facing aspect at 9,700ft. Later that day I found a D1 natural that ran today on another West aspect. These avalanches appeared to run on top of the 3/20 crust.

The NE to E Happy Chutes and Climax chutes had a handful of D1.5 to D2 slab avalanches from the last storm. The crowns were most commonly on the steep 40 to 40+ degree rollers in the terrain.

Weather: Calm to light wind in the valleys. Notable blowing snow off the high peaks in the later afternoon. Mostly cloudy and warm.

Snowpack: I targeted several old avalanche crowns to get a better sense of whether the recent avalanche cycle was breaking in non-persistent storm snow or the well-documented persistent weak layers in the upper snowpack. In each crown I checked out, the avalanche had broken on or below the 3/20 interface, before using the 3/15 interface as a bed surface.

On Easterly facing slopes, the 3/20 interface is a collapsible crust about 1cm to 3cm thick, and the avalanche activity on these aspects had propagated widely across the terrain. The 3/15 interface just made for a nice bed surface on all these avalanches. The crown heights were typically 45 to 65cm.

Where the 3/20 interface was NSF, on northerly facing slopes, the avalanches didn’t propagate as wide.

On westerly aspects, the upper snowpack structure is similar to that found on east aspects. I targeted one test pit on a west aspect 10,500ft, and got an ECTP 23 result on the 3/20 interface. Later I got the remotely triggered avalanche on another west aspect and saw the small nature on another west aspect.

I didn’t observe any obvious signs of instability. The upper slab has settled and gained strength.

Date of Observation: 03/23/2023
Name: Eric Murrow

Zone: Northwest Mountains
Route Description: View from Elkton Knob.

Observed avalanche activity: Yes
Avalanches: Obvious natural cycle on Wednesday 3/22. Numerous avalanches broke near the storm interface on easterly aspects below treeline on Purple Ridge and Schuylkill Ridge near Pittsburg. Many of the easterly avalanches appeared to run late on 3/22. Looking at the up valley end of Schuylkill Ridge there was lots of evidence of avalanches running earlier in the storm but visibility was poor and I wouldn’t see crowns and debris was difficult to read. Atleast one avalanche near the last forested area before the Great Wide Open reportedly ran early Thursday morning. I never really got a good view of Scarp Ridge or the spine of the Ruby Range; I suspect there is more natural activity I was unable to see.
Weather: Mostly cloudy skies with periodic light snowfall obscured views.
Snowpack:

Date of Observation: 03/23/2023
Name: Eric Murrow

Zone: Southeast Mountains
Route Description: HWY 135 observations.

Observed avalanche activity: Yes
Avalanches: A few more unreported slides on Whetstone and Mount Emmons that appear to break only in the recent storm snow.
Weather:
Snowpack:

Date of Observation: 03/23/2023
Name: Dave Kozlowski

Zone: Northwest Mountains
Route Description: Ruby Peak

Observed avalanche activity: Yes
Avalanches: natural avalanche on Ruby Peak.
Weather:
Snowpack:

Date of Observation: 03/23/2023
Name: Eric Murrow

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

Observed avalanche activity: Yes
Avalanches: I will put most avalanche coding and photos in another ob. No natural avalanche activity near TH. View from the top of Elkton Knob was marginal but buffed debris was visible (few crowns) all over the alpine terrain in the Northwest Mountains and covered many aspects; this drifted over natural activity involved storm snow only. Once on top of Elkton Knob there were a lot of widely-propagating crowns visible in the Upper Slate corridor near Pittsburg and on Purple Ridge below treeline. Easterly aspects seemed to be the bullseye below treeline. HIGH danger occurred at all elevations on Wednesday in the Northwest Mountains.
Weather: Mostly cloudy skies with periodic snow showers; no accumulations. Temperatures were seasonally cool, but solar radiation was enough to moisten snow surfaces on sunny aspects. Winds remained light with some moderate gusting up to 11,200. I saw a few periods of blowing snow across the highest terrain during the day. Settled storm totals up to 32″ at 11,000 feet.
Snowpack: The recent storm snow was thick and supportive to skis on all aspects with ski penetration around 7 to 10 inches. I experienced a few muffled collapses that did not travel far. Periodic sunshine moistened snow surfaces on E-S-W slopes below 11,000 feet but failed to warm enough to make loose avalanches an issue. Snowpack tests on easterly slopes produced moderate propagating results (see image) above the melt/freeze crust at the new/old interface. I traveled near several pieces of avalanche terrain trying to get a remote trigger without result; the storm slab is far too supportive and thick to consider ski cutting anything so I kept a safe distance from steep terrain. A profile on a northerly slope did not produce propagating results on the faceted new/old interface (1-1.5mm facets); I was fairly surprised by this given how weak this interface is.

Date of Observation: 03/23/2023
Name: Billy Barr

Zone: Southeast Mountains
Route Description: Gothic Townsite

Observed avalanche activity: No
Avalanches:
Weather: Heavy snowfall Wednesday morning but only light in the afternoon and evening, stopping by midnight. The 24 hour total was 10″ new, with 0.88″ of water content. Wind became off and on, generally moderate with gusting but let up towards sunrise today. Snowpack reached 97″ deep- the deepest on record for March 22. Currently cloudy but calm and not snowing. The 24 hour high was 33 and the low and current 13. Snowpack dropped all the way down to 96½” (at this rate we should hit bare ground by October). billy
Snowpack:

Date of Observation: 03/22/2023
Name: Irwin Guides

Zone: Northwest Mountains
Route Description: Irwin cat-ski tenure.

Observed avalanche activity: Yes
Avalanches: Several, SS-ASc-D1 storm slabs 8-14″ thick on W and S aspects. Party hats L SS-ASc-R2-D2-I. W aspect NTL 14-16″ X 100′ X 800′ Failed on the 3/20 MFC interface.
Weather:
Snowpack: We did not travel E aspects today due to visibility. In the AM storm slabs on W
aspects tittered between stubborn and reactive. 6-8″ storm slabs grew to 12-16″ as the day progressed with
isolated loaded areas up to 24″ thick. By the afternoon avg. crown heights were in the 12-14″ range and
trended towards very touchy with remote triggers up to 25′ away. S aspects reacted vary similar to W BTL/ NTL
today. All were failing on the 3/20 MFC interface. The MFC produced repeat offence avalanches in our tenure
as guides skied certain slopes after snow safety passes.

Date of Observation: 03/22/2023
Name: Eric Murrow

Zone: Southeast Mountains
Route Description: Snodgrass TH up standard skinner with detours to nearby steep terrain features.

Observed avalanche activity: Yes
Avalanches: I remotely triggered two avalanches on a southeast-facing feature below treeline; slides ran on the melt/freeze crust at the storm interface in low density storm snow from the start of the storm. I ski-cut a large Storm Slab that broke on a mid-storm weak layer on an east aspect; as the avalanche ran it propagated wider and down to the storm interface. This avalanche may have collapsed the soft melt/freeze crust beneath the storm snow on east aspects.
Weather: Overcast skies with increasing winds during the day. Strong winds penetrated down to valley bottom during the afternoon. Storm totals ranged from 20-22 inches. From 1030 to 130 snowfall rates were commonly in the 1 to 2-inch-an-hour range. Visibility was obscured all day so I never got a view of the surrounding terrain.
Snowpack: Avalanches in the storm snow were very easy to trigger with some occurring remotely. Low-density snow from the start of the storm remains sensitive to human triggers in sheltered areas. South and southwest-facing slopes below treeline had thick melt/freeze crusts around 4 inches thick below the storm snow and did not appear to cause concern for collapsing. Southeast and east-facing slopes crusts were thinner and may pose a threat for triggered avalanches after issues in the storm snow settle out. I experienced one collapse on an east-facing slope and a nearby test profile suggests that the crust below the storm snow is near its breaking point. I initiated a Loose Dry avalanche down a north-facing slope that gathered a lot of mass, but surprisingly, it failed to release a slab (maybe this slope avalanches the day before). Faceted grains were obvious beneath the storm snow in a north-facing test profile but no propagating results.