Quick report
- Red Flags
- Poor Snowpack Structure
- Red Flags Comment
- <p>Poor snowpack structure observed on NW, N and NE aspects from 9300 to 9700. Of note, the dark layer (that was from the prefontal winds from the inverted event that occurred on the 18th) clearly marked an apparent weak layer that has been reactive since this past storm. As expected, small facets have metamorphised from the light density snow that fell during the initial part of this 35 cm event. At this point in time this weak layer is now buried from 45 to 55 cm down. Other mid pack weak layers were also evident when performing hasty pits on various sites. In more wind exposed terrain locations on northerly aspects, 15 cm buried wind slabs, that are now 30 cm down, have a layer of 2 mm facets below this crust. Also of note were the latest NSF's that formed on the old snow surface before the latest event of thin/light density snow. It appears that the intense cold from the past week has enhanced facet growth in many of these mid pack weak layers. And, it may even be possible that the thin layer of light density snow from today may facet overnight and if not destroyed by the next set of prefrontal winds forecast to occur in the next 24 hours. </p> <p>The only signs of instability were insignificant/small loose snow avalanches, both dry (in the morning) and wet later in the day. The relatively cool temperatures appeared to keep the wet activity at bay until late in the morning, and by 1230 the only sun induced avalanches were observed on SSW aspects. </p>
Snowpack
- Instability Comment
- <p>The past weeks avalanche occurrences into old snow, and mostly triggered by cornice falls, appear to indicate that the weak snowpack structure in the outlying areas where the snowpack remains shallow are still suspect. With the forecast for significant SWE over the next four days, the possibility for a widespread avalanche cycle will be very likely in many areas outside the Alta/Brighton Perimeter.</p> <p>With the forecast for the winds to pick up significantly in the next 24 hours, the potential for wind slab development and even cornice growth/failure appears likely. </p> <p>Danger today appeared to an isolated moderate in rocky, thin snowpack and steep terrain areas; and until the winds change things, the danger would appear to remain the same. Considerable danger appears very possible by the end of the day on Thursday if the wind forecast verifies. </p> <p>Finally, there was an initial Roof Avalanche Cycle today, and there continues to be significant hang fire still in place that has devastating potential due to the thick ice that is at the base of the roof slabs. </p>
1.5 cm of snow fell in LCC and 2.5 in BCC at 8000 feet. Snowfall began around 0500 and was done by 0930. E and SE aspects began getting damp by 1030. NW, N and NE stayed dry and cold throughout the day. Old wind crusts from the last few days of the winds were strewn in the alpine.