We did not observe any recent avalanches, cracking, or collapsing on our tour today. The most recent avalanches occurred 12/23.
Observation: Hatcher Pass
Location: Marmot S Ridge to Mid-rib
From Fishhook lot we toured up the south face of Marmot towards the Mid-Rib. With excellent visibility we were able to see the remnants of older avalanches that ran 12/22-23, including the three that were human triggered on Marmot on Saturday. A common theme was that the older slab avalanches were specific to mid and upper elevation W/SW aspects, with many of them originating from or just below wind-loaded ridgelines. Cornices have been growing in size from strong winds 12/22-24 and were a catalyst for some of these avalanches. Firm snow surfaces are most obvious above 3500 ft and range from 1-4″ in thickness.
Observer Comments
Weather
Cold morning with minus temperatures at the start. Mostly clear skies with light winds from the northwest and evidence of previously blown snow.
Snow surface
Low elevation surface snow looked soft and plentiful with minor wind affect and snow remaining in the trees below 2000 ft.
At mid elevation, we saw previous evidence of moderate wind transport on east to southwest aspects and deposition on west to north aspects. Windward facing slopes have been scoured nearly down to the ground in some locations at upper elevation.
Near 4100' ridgelines, about half way down slopes on leeward aspects the snow was soft with wind deposited snow. In more wind exposed locations we felt the firm wind slab from 12/22-24 underfoot. These wind slabs are buried by 5" of new snow from 12/24.
Snowpack
In our southwest pit location we found a relatively shallow snowpack devoid of firm crust layers. The wind affected snow we did find was below 5 inches of more recent soft snow and was 4Finger hardness. Stability tests conducted found no propagation on the most recent firm wind slab. It was stubborn to fail even with hard forces exerted. The basal layer is rounding facets and may forever linger at the bottom of the snowpack. See picture
12.26 Windslabs at 3600'
12.26 Growing cornices on the Marmot ridgeline
12.26 Old crown on NE Frostbite, likely from 12/22
12.26 Old wind slabs on NE aspect 3500' on Peak 4068'
12.26 Marmot
12.26 Marmot mid rib human triggered avalanche from 12/23 SW 4400'
12.26 Lower Eldorado debris, likely from 12/23
12/26 Dry loose naturals near Martin Mine E 4000'
12/26 Catchers mitt avalanche from 12/23
12.26 pit
Marmot-McRib-26-Dec