Observation: Public

Observation Details

Observed Avalanches

Signs of Unstable Snow

Observations

Snow BTL / before Kautz Creek Crossing at 2.8k' was very stout in the morning, but got punchier as my friend and I ascended. As the day progressed, the crust softened and exhibited more wet loose capabilities, but snowshoe penetration was low (<=2" IIRC). We observed some few days old wet loose debris along the way on south facing aspects. Once we stepped out into more solar-input easterly and south facing aspects, the snow softened considerably and was notably deep in spots (snowshoe penetration was ~1.5'). We treated one area with special care since the runout was poor below and we wouldn't have much of an opportunity to self-arrest before hitting trees or falling off a steep cliff/embankment. I spent some time compressing steps with my snowshoes at lower angles with enough buffer and we went one at a time to help mitigate the risk. After we got above the lower portion of the ridge (~5.3k'), I started noting more wind affected snow (sastrugi in select areas and wind scouring on some south aspects along the ridge) and transport on some north facing aspects. The fetch was incredibly deep (at least 1.5' deep in spots) and there were shallow (1"~2" thick planar) slabs with isolated cracking on top of older wind affected snow. Above 5.3k', the snow became more dry (even mid-afternoon), except in areas where the sun had baked it into a crust. This was especially noted in shaded areas. I saw a few broken crowns: a slightly larger one toward Pyramid Peak near the Tahoma Glacier and a smaller one on the south face of Mt Ararat on the eastern ridge. We were questioning following the down track from skiers, given the mixed wet loose results and snowpack behavior observed on the way up to the summit. I was less concerned about the top layer, but was concerned about the bond with the lower layer, so I stomped on a small cornice overhang on the summit to see how it would react. I used less force at first and more at the end. It was very stout--I was exerting the equivalent of hard (ICT) or higher equivalent force with my snowshoes. It did break RP (a 6"+ slab) once I really started jumping on it though, which concerned me. While the skiers may have triggered surface layer avalanches, I was concerned that my partner and I might trigger deeper snowpack instabilities in the late afternoon with our snowshoe crampons, which could result in D1/D2 avalanches carrying us downhill, since the new storm layer was poorly bonded to the old crust. I discussed my concerns and we retraced our tracks, carefully descending the dicier wet loose section mentioned earlier. The wet loose stability was still poor in solar impacted areas, but had improved considerably in shaded areas. Snow BTL was much less stable below 3.5k'. Snowshoe penetration going downhill was 3"~6" deep in a fairly consistent manner. Wind was variable, but once we got NTL/ATL, it was consistently breezy (L~M), with stronger gusts (M) that seemed to be flowing from Tahoma herself (Pyramid Creek drainage?). Some wind transport was observed coming from north facing aspects, but minimized on other aspects due to the crust(s) present. Sky was bluebird all day on Ararat, but visibility was reduced to 50~75 miles. Snowpack had a fair amount of surface faceting and near surface faceting where wet loose behavior was observed. It wasn't quite corn snow (smaller facets), but it was starting to transition into it.