Date of Observation: 02/17/2023

Zone: Northwest Mountains
Route Description: Up Schuylkill Ridge via OBJ skintrack.

Observed avalanche activity: Yes
Avalanches: D2 natural farther down the ridge on the SE side. Ran within last 48hrs presumably on sun crust storm interface.
Weather: Sun with thin clouds, no wind.
Snowpack: Did get one planar result from hasty hand shear on similar aspect/elevation as observed natural avalanche at storm snow interface (2/15) on small facets 1cm above sun crust.

Date of Observation: 02/17/2023
Name: Zach Kinler and Eric Murrow

Zone: Northwest Mountains
Route Description: Top of the World down to Gothic CG and back. 9,600′-11,500′.

Observed avalanche activity: Yes
Avalanches: Observed a couple of small wet loose avalanches running from rocky, steep south-facing terrain near Mt. Bellview around 12:00 pm. D1 in size.
Weather: Clear skies and calm winds. Below zero temps at the trailhead in the morning gave way to temps at or just above freezing once out of the inversion in the valley floor.
Snowpack: We traveled primarily on slopes facing E-SE-S along the GMT course. No signs of instability were observed underfoot. Open areas near tree line had variable thin wind crusts while sheltered areas were lightly faceted and soft. Snow surfaces on SE and S slopes were moist by midday. HS on an east-facing slope at 10,100 was 185cm. A profile of the upper snowpack on this slope produced 1 hard propagating result and 1 non-propagating result in an ECT on the late January interface. This interface was a thin, 4-finger hard facet layer below a 1-finger slab.

Date of Observation: 02/16/2023
Name: Ben Ammon

Zone: Southeast Mountains
Route Description: Pearl Pass down to Friends Hut

Observed avalanche activity: Yes
Avalanches: 1x D1.5 windslab E aspect Star Peak ran during day 2/15 when winds were out of East (no pic, sorry)
1x D2.5 windslab that stepped down in the rocky break over in several spots, SE aspect of Carbonate (pic attached) Failed during the early AM hours of 2/16
1x D1 Glide slab just above East River, below 4th Bowl (one finally went! Pic attached)
Weather: 2/15 moderate winds out of the East all day, low to no vis, high temps below zero on Pearl Pass
2/16 strong NW winds starting shortly after dark on 2/15, tons of scouring and transport leaving every surface NTL/ATL wind affected, as well as any BTL area not in thick trees. Large plumes (see photo of Pearl Pass) and significant transport on all terrain in the zone (Pearl Pass, Star, Crystal, Carbonate, Timbered Hill) High temp of 4*F at Friends Hut
2/17 Subzero but calm (finally!) and warmed significantly during the day.
Snowpack: A variety of small windslabs that failed during the night of 2/15 or day of 2/16, generally SE aspects, the large Carbonate was the only one of note. Many were partially filled in by the time we made it out skiing on 2/16

Date of Observation: 02/17/2023
Name: Zach Guy

Zone: Northwest Mountains
Route Description: Mineral Point, targeting wind slab instabilities on east to south aspects to 11,600′. Our plan was to cross under the south face of Mineral early morning before it got too warm. After several delays this morning (2 dead car batteries!), we didn’t cross beyond the most exposed sunbaked terrain until 11 a.m., which in hindsight, was cutting it too close for the type of terrain that we were on.

Observed avalanche activity: Yes
Avalanches: A large natural wind slab released off the south face of Mineral around 11:15 a.m., triggered by solar warming or perhaps a very tiny wet loose. The debris washed over part of our skin track that we had set an hour earlier.
Evidence of a widespread storm slab cycle in the Slate during the storm, along with numerous wind slabs in Poverty Gulch that ran after the storm, likely during yesterday’s northerly winds, up to D2 in size. See photos.
Weather: Clear, calm winds. Rapid warming; Double puffy snowmobile ride (-20F at TH), down to sun shirts once we started skinning. At one point, I looked over and my partner’s bare butt was showing, frantically trying to remove his long underwear. haha.
Snowpack: North winds did a lot of damage in Poverty Gulch, with wind slab formation scattered across all elevations. Wind slabs are easy to recognize: smooth, stiff snow (6″ to 12″ thick, 4F to 1F) below rollovers and in gullies, in contrast to softer, rippled sastrugi elsewhere. Wind slab feedback was stubborn underfoot. I snowmobiled and ski stomped on over half a dozen suspect wind-loaded rollovers without any signs of instability or cracking. However, I could produce cracks up to 5 feet while stomping on slopes undercut by the skin track. I also got easy test results on wind-drifted slopes (ECTP1, ECTPV). All of the wind slabs in this area, and my test results, failed on a low-density precip particle layer (non-persistent). Tests on the 2/13 storm interface were unreactive. I tested an east-facing slope near treeline which had a thin crust above facets at the storm interface.

Date of Observation: 02/16/2023
Name: Garrett Eggers

Zone: Southeast Mountains
Route Description: Skied the shoulder between first and second bowl on 2/16. Noticed a fairly wide crown through the trees on a NE aspect in first bowl that appeared to have entrained only the new snow. Probably ran naturally sometime on 2/15.

Observed avalanche activity: Yes

Date of Observation: 02/16/2023
Name: Andrew Payton

Zone: Southeast Mountains
Route Description: ESE chutes directly above Carbon Creek / CR737

Observed avalanche activity: Yes
Avalanches: Two avalanches observed on narrow and very steep east facing chutes on Carbon Peak around 130 pm. They ran about ½ mi / 1600’ vertical. I was cross country skiing up FR563 when I heard the long rumbles about 10 mins apart.

Weather: Sunny, 10 degrees

Date of Observation: 02/16/2023
Name: Rob Strickland

Zone: Southeast Mountains
Route Description: RL to RLB

Observed avalanche activity: Yes
Avalanches: Knocked the small cornice off the summit which produced a small slough and tiny slab… the wind was coming quickly from Redwell and building a small cornice on the south side at this time (730)… while skiing a small slab released naturally from the summit. Lower in the bowl another small slab was released on a steeper rollover.
No one was caught.
Slab size 2 – 4″ deep. maybe 50′ wide. D 0.5

Weather: Sunny & COLD

Date of Observation: 02/16/2023
Name: Evan Ross

Zone: Northwest Mountains
Route Description: Mount Axtell north 9,500-11,500. Evan’s Basin E-SE 9,500-11,300.

Observed avalanche activity: Yes
Avalanches: Looking out from Axtell I just noted a few old, small avalanches near ridgelines. Nothing notable stood out.

Red Lady Bowl looked to have a small wind slab that may have run today, otherwise, it was from yesterday.

One more small wind slab to add onto ZG’s ob that probably ran today in the Whetstone Group. East, 12,000ft.

Weather: Clear and cold. Snow plumes off the high peaks at times throughout the day, becoming more continuous in the afternoon.

Snowpack: On Mt Axtell, the upper snowpack had become notably stiffer when compared to yesterday, from the cold temperatures and previous wind effects. We skied steep slopes to around 40 degrees and didn’t encounter any storm slab avalanche problems. Sluffing was also minimal. Ski quality had decreased from yesterday, but was still good. Recent wind loading patterns are all over the place and not following a specific trend given all the variations in wind direction we have seen. Wind slab travel advice would have been more appropriate than a widespread storm slab avalanche problem today.

Over in Evan’s Basin, the conditions were similar. I didn’t encounter any unstable snow on this quick trip. Wind slab travel advice would have also been more appropriate in that terrain. I targeted a couple of test profiles on east and northeast-facing slopes to look at the 2/13 interface. On a 38-degree east-facing slope at 10,500ft, the 2/13 interface didn’t produce any results and didn’t look very concerning. On a cross-loaded 35-degree NE-facing slope at 11,000ft the 2/13 interface also didn’t produce any test results. Those small facets at the interface were still something to keep an eye on. The density change in the storm snow did produce test results, but snowmobiling through many steep test slopes didn’t produce any signs of instability.

Date of Observation: 02/16/2023
Name: Zach Guy

Zone: Southeast Mountains
Route Description: Mt. Whetstone, viewed from Mt. CB

Observed avalanche activity: Yes
Avalanches: A handful of natural slab avalanches above treeline that ran during the storm, appear to be wind slabs ~D1.5