Date of Observation: 12/09/2021
Name: Ben Pritchett

Zone: Northwest Mountains
Route Description: Kebler Pass and Lake Irwin

Observed avalanche activity: Yes
Avalanches: About a half-dozen small indicator slopes released mid-day Thursday. These all released in facets below the storm snow with around a foot of storm snow.
Weather: 2pm at Lake Irwin: HS 30″, HST 12″, HSTw 1.5″; 2:30pm at Kebler Pass: HST15″, HSTw1.7″.
Snowpack: Whumpf and collapsing where old snow lies beneath the storm snow.
No signs of instability in the storm snow on slopes that were bare ground last week.

Date of Observation: 12/09/2021
Name: Evan Ross and Zach Guy

Zone: Northwest Mountains
Route Description: Schuykill Ridge, traveled mostly on NE aspects to ridgeline at 11,400′.

Observed avalanche activity: Yes
Avalanches: We skier triggered, remotely triggered, or sympathetically triggered numerous soft slab avalanches, D1 to D2 in size, and observed at least one natural. All of these were breaking on the 12/6 facet layer, 30 to 45 cm deep. Most gouged to the ground through loose facets as they descended, or in a few areas, stepped down to the ground through old slab. The most notable slides were: 1) A skier triggered D1 slab in Runaway Ski that sympathetically pulled out a D1.5 in the same path, which then sympathetically pulled out a D2+ in Thanksgiving Bowl. 2) Yogi’s ran naturally to the bench, D2 in size 3) From ridgeline, we remotely triggered a D2 slide in Thanksgiving bowl that looks like it sympathetically pulled out another D2 in Birthday Bowl. From this same location, or shortly after nearby, we also remotely triggered another D2 in Runaway Ski. We measured the debris pile below Thanksgiving Bowl at 2.5 meters deep, and it snapped a few small trees. All slides stopped at the midway bench. We also triggered a handful of smaller slides below the bench in areas that might surprise you because of how bushy it is.
Weather: Light to moderate snowfall throughout the day. Strong southwesterly winds at ridgetop were drifting snow.
Snowpack: 10″ to 15″ of storm snow over the well-described 12/6 facet layer. Extensive shooting cracks on all open slopes that we traveled. Near windloaded ridgeline, slabs were 2 feet thick and we also got a couple of audible collapses there. Ski pen is close to the ground through the soft new snow and faceted old snow; HS is generally about 2 to 3 ft deep.

Date of Observation: 12/09/2021
Name: Mark Robbins

Zone: Northwest Mountains
Route Description: First toured from the bridge past pittsburgh up the sw facing rollers on the ne side of the road, up to 10,500 or so. Snowpack was 10-12 inches of storm snow to grass and rocks and stumps.
Then crossed the creek to go check in on more northerly aspects. Natural avalanche by the residential bridge crossing the creek, see photo1. Toured up to the first flat field and remote triggered a storm slab on the first ledge, from the flats about 30 yards away, see photo2. A little further on, shooting cracks fractured a slope, reaching 30 yards or so, see photo3 and photo4. We stomped around trying to get more activity, and then tucked tail back to the sleds.

Observed avalanche activity: Yes
Avalanches:
Weather: Windy and snowy. Maybe 3 inches of accumulation during the 3.5 hours we were out there.
Snowpack:

Date of Observation: 12/09/2021
Name: Travis Colbert

Zone: Southeast Mountains
Route Description: I know Roman & Vandenbusche think ski-mo is silly, but I imagine a few of you might be wondering what conditions are like on Snodgrass after this most recent snow. After a near-miss (thanks ZK!) on the wall-to-wall D 0.1 (could bury a tea-cup Schnauzer but thankfully not an 80 pound Blue Heeler) on this morning’s dog walk, I decided to head on up to the newly constructed and hotly contested parking area at the base of Snodgrass Mountain. Both lots were freshly plowed and empty, so I took the first of many parallel parking spots closest to the start of the ascent. I found 6-7″ of fresh snow on what previously had been dry ground. It seems that much of the road had been dry prior to this storm, so ski pen was nearly to the ground for most of the climb. I diverged from the road at one point, but would not recommend as coverage in the forest is very thin. After establishing a little north side observation loop at the top of the road and stomping out a nice pad for ripping skins (got to work on those quick transitions if you want to be any good at ski-mo), I scooched back down the up-track for another lap. I didn’t make a single turn for fear of clipping a rock (especially on the lower third). Hopefully after tonight’s storm, coverage (on the road at least) will not be an issue. Have fun out there and be safe!

Observed avalanche activity: No

Date of Observation: 12/09/2021
Name: Joey Carpenter

Zone: Southeast Mountains
Route Description: Toured up the ‘normal’ Coneys skinner until the downed trees became unbearable then traversed out onto what was (a few days ago) the bare side of Convex Corner.

Observed avalanche activity: Yes
Avalanches: Was able to get one small pocket to pull out via ski cut on the far right edge of photo. <TL-NE-SS-ASi-R1D1. About 50 feet wide and ran around 20 feet.
Weather: Relatively warm, light to no precip from 6:30a-8a while I was out. Light winds from the W at ridge top, calm below. Overcast.
Snowpack: ~8 inches of new snow from yesterday/last night. On the sunny side sitting on the ground and in shaded areas sits on a rotten base that varies in depth up to an additional 7-8 inches (estimated). Several small whumpfs and associated cracking while traveling through undisturbed areas where base snow was present. Storm snow hadn’t gained enough slab structure yet to release with much energy, which will quickly change as this second pulse of snow comes this afternoon.

Date of Observation: 12/09/2021
Name: Evan Ross

Zone: Southeast Mountains

Weather: Snow started mid afternoon and was generally light, picking up after dark for abut 3 hours and then light through the night. Temperature rose into the night and that and some wind made for a dense snow. The 24 hour total was 7″ new and water 0.61″ and the snowpack sits at winter’s deepest o 11″. Wind was moderate and moved snow, becoming calm around 4 a.m. Currently obscured with light snow and 25F after an overnight low of 24 while high was 28. And away we go.

Date of Observation: 12/08/2021
Name: Zach Guy

Zone: Northwest Mountains
Route Description: Quick morning tour in the Upper Slate, traveled on East to North facing aspects to 12,000 ft.

Observed avalanche activity: Yes
Avalanches: Skier triggered a few shallow wind slabs on crossloaded northeast aspects near and above treeline. Slabs were up to 10” thick, didn’t run far, and failed on the Dec 6 facet layer.
Weather: Light winds, clouds increased to overcast by 10 am. Very light snowfall started at 11 on our way out.
Snowpack: The few inches of Tuesday nights snow started faceting overnight, and is currently not bonded well to underlying melt freeze crusts. Thus, I expect aspects with a crusty 12/6 interface to be problematic with this incoming storm as well, at least in the short term. Shady aspects are already demonstrating their poor bonding to 12/6 with easily triggered pockets and cracking anywhere that there’s been enough wind transport for slab formation.

Photos:

Date of Observation: 12/07/2021
Name: Eric Murrow

Zone: Northwest Mountains
Route Description: Upper Slate River up the standard track to ridge and followed ridge to 12,000 feet.

Observed avalanche activity: Yes
Avalanches: Visibility was obscured by low-level clouds during my tour so I did not get any views of drifted terrain in the Ruby Range. I intentionally triggered a shallow slab by kicking a cornice on an east slope at 11,800 feet, D1 in size – hardly big enough to knock you over let alone carry you. Max crown depth was 10 inches but only extend downslope 15 feet, slowly ran 150 vertical feet.
Weather: Mostly cloudy skies with low cloud cover obscuring visibility. Sporadic snow showers without any accumulations during the day. Moderate westerly winds above treeline.
Snowpack: I measured 4.5 inches of new snow at 11,200 feet. I walked along an east-facing ridgeline from 11,500 to 12,000 feet assessing slab thickness on drifted terrain and found fresh cornice formation up to 18 inches thick and slabs up to 10 inches thick but slabs quickly tapered off once 20 feet below ridgetop. Cracks ran up to 30 with just a single very small avalanche triggered. Snow available for transport on the adjacent westerly terrain appeared to have largely run dry.

I dug to profiles on easterly aspects at 11,500 feet. One was on the southern edge of east at 105* and I found 5 inches of storm snow resting above a stack of melt/freeze crusts that were connected by ice columns from meltwater during last week’s record high temperatures. This structure appeared quite strong and would tolerate a very large load prior to collapsing (see photo). On the northerly fringe of east aspect at 75*, I found a snowpack that was largely free of melt form grains with several prominent weak layers that formed between each storm during November (see Snowpilot profile).

While descending below treeline I ski cut some tiny facet sluffs on northeast-facing slopes. The facet sluff’s entrained about 10 inches of snow as they ran.

Photos:

Date of Observation: 12/06/2021
Name: Travis Colbert

Zone: Southeast Mountains
Route Description: Drove up Washington Gulch to the 403 TH to observe the snow coverage prior to this week’s storms.

Observed avalanche activity: No
Avalanches:
Weather: Light flurries as incoming storm system was just arriving.
Snowpack: Shallow and patchy. Coney’s had continuous (and weak) coverage; south and west side of Gothic was bone dry (except for NW aspects); SE & SW slopes around Elkton were dry.