If we wake up to more than 20 cm of storm snow, then these danger ratings should all be bumped up one level, so moderate becomes considerable. New snow and wind Saturday night may produce a natural avalanche cycle if the "Fernie Factor" kicks in...
Summary
Confidence
Low - Timing, track, or intensity of incoming weather system is uncertain on Saturday
Weather Forecast
A frontal system should track into the region late Saturday into Saturday night. We're expecting it to be quite convective which makes it hard to pin down total snow amounts, but right now it sounds like the storm could produce up to 10 cm before dark, and another 8 to 15 cm Saturday night, possibly more if the notorious Fernie Factor kicks in.SATURDAY NIGHT: Freezing level around 1500 m, moderate to strong southwest wind, 8 to 15 cm of snow.SUNDAY: Scattered cloud cover initially building to broken cloud cover in the afternoon, freezing level around 1600 m, moderate to strong west/southwest wind, 4 to 8 cm of snow possible. MONDAY: Scattered cloud cover, freezing level rising to around 1700 m, light variable wind, trace of snow possible. TUESDAY: Scattered cloud cover clearing to just a few clouds around lunch, freezing level rising to around 2000 m, light variable wind, no significant snowfall expected.
Avalanche Summary
On Friday small loose wet natural avalanches were reported from steep south facing terrain.On Thursday, explosive control was able to initiate a few loose dry avalanches up to size 1.5 which failed in the recent storm snow. In the afternoon skier controlled loose wet avalanches were easily triggered at treeline and below up to size 1.5 on sunny aspects. No natural avalanche activity was reported and no new avalanches were noted in alpine elevations.
Snowpack Summary
15 cm Thursday night brings 20-35 cm of recent accumulated snow since last weekend which sits above a supportive crust at treeline and in the alpine. During the heat of the day, especially under direct sun, the snow surface becomes moist or wet almost everywhere. The exception being high elevation north facing features. Steep, north facing, alpine terrain may still hold a cold, dry, snowpack where isolated reactive wind slabs may exist and a well settled slab rests on weak facets (sugary snow). Although unlikely, human triggering of persistent slabs on this layer may still be possible, especially in rocky alpine terrain with a shallow or highly variable depth snowpack. Below treeline the snowpack is becoming
isothermal.
ghelgeson,
Avalanche Canada
