South Columbia

A Special Public Avalanche Warning is in effect.

Fair - Timing, track, or intensity of incoming weather system is uncertain

On Sunday, expect 5-10 cm snow and moderate to strong SW winds. Snow eases to light amounts on Monday, then the next pulse begins on Monday night, bringing around 5-15 cm snow with moderate to strong SW winds. Freezing levels are between 1800 m and 2200 m, dropping on Tuesday to around 1600 m.

A widespread avalanche cycle ran on Thursday and Friday in response to wet and windy conditions. These were a mix of storm slab, loose wet avalanches and persistent slabs, up to size 3. A few remotely triggered avalanches were also reported.

Strong winds have shifted snow onto lee slopes at high elevations. Rain on Friday soaked the upper snowpack to at least treeline. Two persistent weak layers in the upper metre or so of the snowpack are the main story. They have been keeping conditions spicy. The mid-March layer, around 60 cm down, is most reactive where it exists as a crust. Around 80-100 cm down, the mid-February facet/crust interface has also been reactive with large loads like smaller avalanches stepping down, cornice fall or explosives. Both layers are sensitive to triggering and propagate easily, causing very large avalanches.