Purcells

Lingering wind slabs may remain surprisingly reactive to human triggers in areas where they are sitting on top of a layer of small surface hoar.

 SUNDAY NIGHT: Mostly cloudy / Light, southwest wind / alpine low temperature -15 / Freezing level valley bottom.

 MONDAY: Snow, 5-10 cm / Light, west wind / alpine high temperature -8 / Freezing level valley bottom.

TUESDAY: Sunny / Light, west wind / alpine high temperature -7 / Freezing level valley bottom.

WEDNESDAY: Sunny / Light, south wind / alpine high temperature +1 / Strong inversion with an above freezing layer of air above 2000 m.

Check out this notable MIN report of numerous human triggered avalanches from Quartz Creek on Saturday. The recently buried layer of small surface hoar that caused this avalanche could likely catch riders by surprise.

Data is very sparse in this region. Please submit your observations to the Mountain Information Network.

  Recent strong southwest winds have created fresh wind slabs on lee features at treeline and above. There have been a couple human triggered avalanches on a recently buried layer of small surface hoar. This layer has been reported as "spotty" and is most likely to be present in sheltered areas. There is a crust from early November that is down approximately 50-75 cm. This layer has been observed to have weak, sugary facets above and below it and is most likely to be reactive to human triggers on south facing slopes and in shallow, rocky, snowpack areas in the alpine.

• Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
• If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
• In times of uncertainty conservative terrain choices are our best defense.
• Closely monitor how the new snow is bonding to the old surface.
• Carefully assess open slopes and convex rolls where buried surface hoar may be preserved.