Avalanches: See photos. A handful of large natural slab avalanches on leeward terrain near and above treeline (easterly aspects) that all look like they ran last night or yesterday afternoon. Most appear to be on the 1/19 facet layer, and a few wind slabs.
Photos:
Schuylkill Ridge, D2 East NTL
Gothic: Several D1 to 1.5 wind slabs East ATL (sorry about the blurry photo)
Zone: Northwest Mountains Location: Upper Slate Aspect: North East, East, South East, West Elevation: 9700 – 10900′
Avalanches: Ski cut a couple of thin wind slabs below treeline, about 6″ thick, that formed this afternoon, D1.
Got good views of the large avalanche reported yesterday from Schuylkill Ridge. Based on the size of the crown, I estimate that it failed on the 1/19 interface about 18″ deep and gouged near to the ground. That path ran in mid-December and the snowpack prior to this recent storm was very thin. See photo.
Saw another persistent slab (probably 1/19 interface) that likely ran in the past 24 hours, triggered by a sluff from a cliff band above on an east aspect BTL. D1.5
Had good views of other terrain visible from the Slate River Road and didn’t see anything else noteworthy. Weather: Light snowfall (S-1 to S1) started around noon, with a few moderate pulses (S2) mid-afternoon. W/NW winds showed up around 2 p.m. – moderate with strong gusts produced light to moderate snow transport where we traveled, which was mostly below treeline. Snowpack: Recent storm snow has settled noticeably since my tour yesterday on Kebler Pass. There’s about 16″ of F+/4F- soft slab over the 1/19 interface. We experienced a couple of large collapses and a handful of smaller, muffled collapses. A few stability tests on both east and west aspects below treeline showed similar structures and non-propagating results. The snow surface was getting denser due to this afternoon’s winds.
We kept to generally simple terrain and a few short, steeper pitches. We didn’t have any avalanche encounters other than some small wind slabs.
Photos:
Skier triggered 6″ wind slab. East aspect BTL
Recent natural persistent slab (D1.5), East aspect BTL
The crown of the skier triggered avalanche on Schuylkill Ridge yesterday.
Zone: Southeast Mountains Location: Coney’s and Snodgrass Aspect: North East, East, South, South West, West Elevation: B/NTL
Avalanches: Observed debris below the West Face of Gothic. Looked fairly fresh but visibility was mediocre so hard to say from when, could not see start zones well enough to tell. Weather: Overcast with periods of broken skies until around 230pm, with on and off S-1 and very light to calm winds. After 230pm winds were moderate from NW and S1 snowfall. Snowpack: Storm snow much more supportive today, 4F to F+ right above the 1/19 interface. Traveled a few of the same zones Saturday on the tail end of the largest snowfall and could still feel old tracks despite very deep conditions, but today was a different story! Traveled on terrain up to the low 30 degree range facing NE, E, S, SW, and W. Observed no signs of instability, observed generally excellent ski quality.
Weather: This is now the 8th day in a row with measurable snowfall and only one day has recorded more than 2½”. A true sign of a winter in drought. Light snow yesterday, then some clearing after dark as temperature dropped to -09ºF before clouds moved back and pushed it to the current 6F after a high yesterday of 24F. Light snow with 1″ new and water 0.09″. Currently overcast with very light snow, though small and dense crystals without any wind and snowpack sits at 35″. billy
Zone: Northwest Mountains Location: Schuylkill Ridge Aspect: North East Elevation: Near treeline
Avalanches: Skier triggered a large slide that “ripped to the ground…released way above me”. Skier was able to get out of the way of moving debris due to good radio communication from partners watching from a safe spot.
Date of Observation: 01/25/2021 Name: Jack Caprio and Zach Guy
Zone: Northwest Mountains Location: Ruby/Dyke area, then Anthracites Aspect: North, North East, East, South East Elevation: 10,000-11,500
Avalanches: We remotely or sympathetically triggered 6 D1 to D1.5 persistent slab avalanches on east facing terrain near and below treeline.
1 remotely triggered D1 on an east facing near treeline slope off Ruby Peak. This avalanche was triggered from about 200 vertical feet below. The crown was 18 inches of recent storm snow on facets ( 1/19 interface).
In the Anthracites, we continued to find instabilities. We remotely triggered one D1.5 soft slab avalanche which then sympathetically triggered 4 more small avalanches (D1 to D1.5) on the same terrain feature. All of these failed on facets just below the 1/19 interface with the crowns ranging from 24-30 inches of soft (F hard) storm snow. We also ski triggered a similar slide on a small rollover.
We observed a handful of natural soft slab avalanches that likely ran on Saturday, D1 to D1.5:Â 2 on east facing terrain below treeline, 2 on southeast facing terrain below treeline, and 1 on a southeast aspect near treeline.
Weather: Overcast skies with moderate snowfall all morning (S2) near Lake Irwin. We made our way over to the anthracites around 11:00 am where we were welcomed with broken skies and the occasional pulse of very light snowfall (S-1).
Snowpack: We generally found about 18-30 inches of recent F to F+ hard storm snow sitting on top of the 1/19 interface. This interface consisted of a thin, weak MF crust capping facets on southeast aspects and facets or facets below a thin wind crust on due east.
On east facing terrain below Ruby Peak, several collapses and an easily propagating extended column test (ECTP5) turned us away from some steeper and more consequentail terrain options. A couple of steps after the snowpit test, we remotely triggered a D1 soft slab from 200 vertical feet below the slope.
At the Anthracites, we took our first run on a north facing, below treeline slope. We did not observe any signs of instabilities aside from sluffing and a small pocket on a rollover. Stepping off the skin track near ridgeline, we observed several rumbling collapses on southeast, east, and flat slopes, along with shooting cracks. On our second run, traveled near some open, east facing terrain that had seen more wind loading, and produced a mess of avalanches from one remote trigger 50 feet from steep terrain
6 remotely/ sympathetically triggered persistent slab avalanches failing on the 1/19 interface continue to prove that this snowpack is setup for failure. In most snow-favored areas of our forecast zone, especially on leeward terrain features, we continue to find a grim persistent slab structure that is only in its infancy of causing problems.
Photos:
Easy propagating results on the 1/19 interface
Remotely triggered persistent slab from 200 feet away
Natural D1.5 slab in East Bowl of Anthracites, likely ran 1/23
Natural D1 slab SE aspect BTL. Anthra
Small pocket triggered on a north aspect BTL
Shooting cracks spanning the whole slope. East aspect NTL
Weather: Cloudy all day yesterday and overnight with steady very light snow during the Sunday morning – a cold weather, small crystal, dense snowfall but not much of it until a brief last afternoon period of heavier snow. Then dry most of the night until snow started up around 5 a.m. Snow total is 3″ new and 0.29″ of water and the snowpack sits at 36½”. No wind (and none yesterday) and currently overcast and the snow seems to have stopped. The temperature range was a hgh of 27F, low 0F and currently 10F. billy
Avalanches: 1 small storm slab from Saturday 1/24. North aspect at 10,000ft.
Weather: Overcast. Pulses of snow, ramping up the most in the afternoon. Picked up 3 to 4″ of new snow today.
Snowpack: Traveled through lots of terrain, but mostly lower angled slopes. Not much for red flags until we were riding slopes in the low 30-degree range on E, SW and W aspects between 11,000-12,000ft. Farther running shooting cracks in this terrain make it clear that we didn’t want to travel on anything big or much steeper. These slopes were upper BTL and NTL type terrain and didn’t have recent wind-loading.
Small storm slab avalanche from 1/23. North Aspect 10,000ft.
Deep, soft drifts. NTL near Scarps Ridge.
Very quick hasty pit after triggering long-running shooting cracks. Low 30 degree W facing terrain at 11,600ft. Cracks were propagating on the F hard facets near the ground.
Date of Observation: 01/24/2021 Name: Sasha Legere
Zone: Southeast Mountains Location: Red Lady Skin Tracks Aspect: South East Elevation: 11800
Avalanches: Watched it slide from the Red Lady skin track. No obvious trigger. Possible natural slide but did see some tracks on the ridge above the slide on our descent so possibly remote trigger. Weather: Low visibility. Light snow. No wind. Snowpack: Storm Slab
Date of Observation: 01/24/2021 Name: Bo Torrey (Public)
Zone: Northwest Mountains Location: Red Lady Glades 11,800′ Southeast Aspect (38.8694561, -106.9856561) Aspect: South East Elevation: 11800
Avalanches: R1, D1, storm slab. Natural slide – Not human triggered. Watched it go. Weather: Snowpack: Around 10 inches of new snow slide on a shallow snow pack
