Avalanche Forecast

SATURDAY NIGHT: Partly cloudy, light northwest winds. Isolated flurries possible. Freezing levels drop to valley bottom. 

SUNDAY: Strong sun, light westerly winds becoming moderate in the late afternoon. Freezing levels rise to 1500 m. Alpine high of -2. 

MONDAY: Cloudy with isolated flurries bringing up to 2-8 cm of snow, moderate to strong northwest winds. Freezing levels rise to 1500 m, alpine high of-2. 

TUESDAY: A mix of sun and cloud with isolated flurries. Light northeast winds. Freezing levels at valley bottom. Alpine high of -6.

While storm slab activity continues to gradually taper off, recent activity indicates the impact of the sun on surface weak layers. On Friday, numerous storm slabs were naturally triggered by solar input on south and east facing slopes to size 2.5. On north facing slopes (not affected by solar), storm slabs were still reactive to human triggers to size 2. In general, storm slab avalanches have been more frequent and larger in the Selkirks than in the Monashees.

Over the past two weeks we have seen large (size 2 to 3) persistent slab avalanches on buried surface hoar and crust layers. Most of the activity has been in the Valhalla, Goat, and Kokanee Ranges at treeline elevations. Activity reported on Friday included:

• A size 2 triggered by a snowmobile on a northeast aspect at 2200 m near Slocan, failing on the late February weak layer up to 100 cm deep. Read the MIN report here for full details. 
• A size 2.5 naturally triggered in the Valhallas - likely by solar input on an east facing slope at treeline. This avalanche is believed to have failed on the mid January weak layer, around 50-100cm deep.
• Nearby another size 2 was remotely triggered by riders on a scoured ridgeline, failing on the mid February melt freeze crust. The avalanche occurred on a wind loaded convex roll on a northeast slope at treeline. 

Recent storm snow has settled into 30 to 50 cm of heavy powder at upper elevations.On sun affected slopes and lower elevations (below 1800 m), surface snow has become moist and crusty. 

The new snow sits over a reactive crust-facet-surface hoar combination. This interface continues to produce human and triggered avalanches on all aspects, and naturally triggered avalanches on sun affected slopes. 

Buried weak layers sit 50-100 cm deep, buried between mid February and mid January. They both consist of surface hoar and/or melt-freeze crusts. Recent trends indicate these layers have been more reactive in southern Selkirks around the Valhalla, Kokanee, and Goat Ranges. Several natural and human triggered avalanches have been produced on these layers in the last 3 days. See the Avalanche Summary for full details

• Don't be too cavalier with decision making, storm slabs may remain sensitive to human triggering.
• Be aware of the potential for large avalanches due to the presence of a persistent slab.
• Carefully assess open slopes and convex rolls where buried surface hoar may be preserved.
• Avoid exposure to steep sun exposed slopes.