South Columbia

A widespread natural avalanche cycle is expected to begin Monday and climax on Tuesday. Conservative terrain choices will be critical in the days to come.

Stormy weather forecasted though Tuesday. 5-15cm of snow throughout the day and overnight on Sunday with strong-extreme southwest winds. Another 10-15cm of snow throughout the day on Monday with moderate southwest winds and 1500m freezing levels. Tuesday is the big day with 15-25cm of snow throughout the day, extreme west winds, and freezing levels spiking to 2000m. The storm tapers on Wednesday with light winds, flurries, and lowering freezing levels. Expect actual snow amounts to vary throughout the region with generally lower amounts in the south.

On Saturday, several natural avalanches were reported up to size two, at treeline and below, on all aspects. Natural avalanching likely occurred in the alpine, but was not observed.

10-20cm of new snow Sunday morning brings recent storm snow totals to 40-60cm. This storm slab sits over a variety of old surfaces, including wind-stripped north aspects, hard wind slabs, facets, sun crusts and/or large-sized surface hoar. The weakest of these interfaces is a layer of surface hoar which can be found below approximately 1800m on all aspects. The mid and lower snowpack is generally well settled. However, 120-150cm down, a surface hoar interface that was formed in November has been dormant but still may wake up with heavy loading or smaller avalanches stepping down.

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