Quick report
- Red Flags
- Recent Avalanches, Wind Loading, Cracking, Collapsing, Poor Snowpack Structure
- Red Flags Comment
- <p>Noted a couple small D1s off the rocks on the S-E aspects of Willard Peak, as well as a longer running D1 directly down the lower half of the S face of Island Peak. Unable to see anything higher up as clouds regularly obscured summits and ridgelines. </p> <p>Several red flags today with cracking, collapsing, whumpfing from NW to N to E. It was a bit challenging to correlate collapsing with specific problems/layers, but we had collapsing as low as 6300ft to as high as 8300ft (our high point for the day). Failures seemd to be more common with softer overlying slab (as opposed to generally firmer wind slab). Best guesses are this was either due to wind affected terrain having firmer snow throughout in general due to prior wind effects, or maybe bridging across zones of potential collapse as shrubs, trees, and rocks made for a fairly discontinuous snow surface nearly everywhere. Collapsing/cracking ranged from only under foot to cracks of a dozen yards or more, with sensitivity from very touchy to rather stubborn.</p>
Didn't dig any formal pits today as there was plenty of other bullseye information to be had. However, snowpack structure was as might be expected--new snow (and/or wind affected) on top, ceiling to floor facets below this. Basal facets were pretty damp at low elevations, becoming progressively drier, but still a bit moist, above 8000ft. Failures were in the top 20cm or so of snow on the new/old interface (or wind affected/old interface as the case might be). The old snow surface was NSF in all locations where we had collapsing/cracking. Below 7400ft or so, we also found buried surface hoar atop the NSF in places, especially below about 6700ft. Some of this was quite well developed, with cups present that would typically be reserved for depth hoar. The silver lining to this is that at low elevations, it's challenging find a big enough and deep enough pocket of continuous snow to make a large avalanche.
Snow depths progressed from about 45cm at 5600ft to 80-90cm above 8000ft, and surely cresting 1m at points beyond 8500-9000ft or so.
A relatively representative photo below of cracking/collapsing today.
Failing slabs were about 20cm thick, ranging from F to 1F, with some cohesive 4F seen here (inverted with NSF on top in the photo).
Old surface facets seen here, with surprisingly well developed cups that resulted in a very touchy collapse.
A general view of current coverage on the Cutler headwall.
Snowpack
Ben Lomond picked up 2-3" of snow overnight and into the morning. Snow surface was a mix of graupel, rimed stellars, and wind affected. Graupel dominated low elevations, with some stellars mixed in higher up. From 7800ft and above, much of the snow surface had at least some wind affect, but varied with F new snow, 4F storm slab, 4F wind slab, and 1F wind slab. The local N winds noted above were readily transporting snow. However, this wind transport was "backwards" compared to normal, so travelers familiar with Cutler Ridge should expect to find corncies and wind slabs in unusual locations the next day or two until things settle out.