Purcells

Dangerous avalanche conditions exist in the alpine where new snow continues to incrementally add load to buried weak layers. Carefully evaluate terrain as you move through the backcountry and when in doubt choose conservative terrain.

• Be especially cautious as you transition into wind affected terrain.
• Potential for wide propagation exists, fresh slabs may rest on surface hoar, facets and/or crust.
• Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.

On Monday, several small (size 1) natural loose dry avalanches were reported on steep northwest alpine slopes.

A fatal avalanche occurred on April 15 in the Thunderwater Lake riding area, just west of this region. The avalanche was triggered near a rocky area and was very large (size 3). Two riders were caught, one was buried approximately 2 meters deep. Despite an immediate extrication rescue response, the rider did not survive. Any additional information we have on this accident can be found in this MIN.

If you are getting out in the backcountry, consider making a post on the MIN (Mountain Information Network).

At treeline and above, 15 - 40 cm of recent snow is being redistributed by variable winds into soft slabs in lees. This overlies a variety of crust, surface hoar and/or facet layers that were buried in mid March through early April may exist in the upper snowpack. Recent avalanche activity in adjacent regions indicate that these interfaces contributed to the current avalanche problem there. Most professional operations in the forecast area are tracking their own local layer of concern to see if they become active with increasing temperatures, or more load from new rain or snow.

Below treeline, expect to find moist or refrozen surfaces, and shrinking snowpack depths.

The mid snowpack is generally settled and strong, although west of Invermere, some professional operations are still monitoring a layer of weak, feathery surface hoar crystals that was buried in mid January.

The lower snowpack includes a widespread layer of large, weak facets and/or depth hoar crystals. This weak layer has been responsible for several very large and destructive avalanches throughout the season.

Tuesday Night

Cloudy with scattered flurries, 3-4 cm accumulation. Light variable ridgetop wind. Freezing levels drop to 800 m. Treeline low around -6 °C.

Wednesday

Cloudy with scattered flurries, 2-5 accumulation. Light variable ridgetop wind. Freezing levels rise to 1400 m. Treeline high around -4 °C.

Thursday

Mix of sun and cloud. Light northwest ridgetop wind. Freezing levels rise from valley bottom to 2000 m by mid-day. Treeline high around 0 °C.

Friday

Mix of sun and cloud. Light southwest ridgetop wind. Freezing levels rise from valley bottom to 2000 m by mid-day. Treeline high around 0 °C.

More details can be found in the Mountain Weather Forecast.