Avalanche Forecast

A couple natural and rider triggered wind slab avalanches up to size 2.5 at treeline and above were reported on Thursday.

Additionally, explosive control work north of Nelson produced two large (2-2.5) deep persistent slab avalanches on southwest and southeast aspects beneath treeline ridgetops. These avalanches occurred on slopes that had previously avalanched on the November facet layer.

Strong easterly wind has formed fresh wind slabs on lee aspects at treeline and above. These slabs are sitting on a sun crust on sunny aspects or surface hoar (5-10 mm) on shady aspects at all elevations.

A layer of surface hoar or sun crust (aspect dependent) can be found down 50-70 cm.

The lower snowpack includes a layer of weak sugary crystals near the ground. These facets are slowly gaining strength and have not produced recent avalanche activity. We continue to track the layer and watch for any signs that it could wake up and produce very large avalanches.

Friday Night

Cloudy with isolated flurries; 3-5 cm / Light west ridgetop wind / Low temperature at treeline around -8 C / Freezing level valley bottom.

Saturday

Cloudy with flurries; 3-10 cm / Light southwest ridgetop wind / High temperature at treeline around -2 C / Freezing level 1200 m.

Sunday

Mostly cloudy with isolated flurries; 0-5 cm / Light southwest ridgetop wind / High temperature at treeline around 1 C / Freezing level 1500 m.

Monday

Snow; 15-20 cm / Strong southwest ridgetop wind / High temperature at treeline around 2 C / Freezing level rapidly rising to 1800 m.

More details can be found in the Mountain Weather Forecast.

• Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
• Avoid shallow, rocky areas where the snowpack transitions from thick to thin.
• Use extra caution around cornices: they are large, fragile, and can trigger slabs on slopes below.