Public Observation

Observation Details

Signs of Unstable Snow

Observations

Terrain: We rode snowmobiles to 5500 ft and toured to Lockwood Point. We traveled through protected and wind affected terrain on SW to N aspects. We chose to close wind loaded terrain over 35 degrees today.

Weather: Initially temps were mild with calm winds. By midday temperatures dropped and light to moderate winds were present out of the north. Snowfall throughout the day was light, S1 to S3 intermittently. Visibility was limited in the morning and clearing by the afternoon.

Snowpack: While touring we remarked at how little apparent wind affect there was on the new storm snow, however we did find isolated wind slabs, about 6in deep at ridge-line on an easterly aspect. We toured through areas where we could feel the new snow fell upside down, or heavy snow on top of weaker, cold, low density snow. These areas showed signs of instability, but the overlying slab, about 6-8 in, was not very stiff. This layer could prove problematic with more wind, or warmer, more dense snowfall. Snow surfaces on all aspects were cold, loose, and dry.

We dug one pit on a southerly aspect and an ECT was inconclusive. We did not find any large basal facets or obvious layers of concern. HS was 115cm at 6700'. We dug another pit in a protected north facing aspect at 6800' looking for weak layers from earlier this season. We found moist facets at the base of this snowpack, and two old ice crusts at about 20 and 30cms from the ground. HS here was 140cm.

Overall today we did not observe any obvious red flags. We finished our tour before this incoming storm pulse arrived. There is a lot of dry snow available for transport, and any new, denser snowfall will land upon dry weak storm snow. We choose mellower terrain today and avoided wind loaded slopes, terrain traps such as gullies, and skied conservatively.