Storm slabs will remain most reactive where wind continues to load deep deposits onto leeward slopes. An upside-down configuration over a weak layer in the upper snowpack means that reactivity may persist for longer than usual after the storm.
Storm slabs will be most reactive where deeper deposits have been wind loaded into lee aspects. Avoid these areas until they have a chance to stabilize. Recent snow rests on a weak layer which means that reactivity may persist for longer than usual after the storm.
Saturday night: 5-10 cm of new snow. Strong to extreme southwest wind. Treeline temperatures around -1 C. Freezing level 1400 m.
Sunday: 5-10 cm of new snow. Strong southwest wind easing through the day. Treeline temperatures around -6 C. Freezing level 1000 m.
Monday: 5-10 cm of new snow. Moderate southeast wind. Treeline temperatures around -4 C. Freezing level 1000 m.
Tuesday: A mix of sun and cloud. Light wind. Treeline temperatures around -8 C. Freezing level 500 m.
We are still awaiting observations of avalanche activity during the storm. Skier control work near Nelson produced storm slabs up to size 1.5 and explosive control work in Kootenay Pass produced storm slabs up to size 2.5. These avalanches were 30-50 cm deep, failing on the thick crust layer described in the snowpack summary.
Ongoing snowfall and wind will continue to load leeward terrain features at upper elevations Sunday. An upside down upper snowpack has resulted from 15-30 cm of warm snow falling over unconsolidated low density snow sitting on a thick crust. This crust, now 40-70 cm deep, is well detailed in this MIN report from before the storm. Snow depths are roughly 80-140 cm at treeline.
