If sunny skies, and solar radiation occur. Southerly slopes may deteriorate, and natural avalanche activity could spike.
Summary
Confidence
Fair - Timing, track, or intensity of incoming weather is uncertain
Weather Forecast
A ridge of high pressure moves inland bringing dry, warming conditions until Friday. A frontal system tracks inland from the coast, allowing a southwesterly flow and unsettled conditions. Thursday: Dry, mix of sun and cloud. Ridgetop winds moderate from the West. Treeline temperatures near -3. Freezing levels 12-1500 m. Friday: Snow amounts near 10 cm. Ridgetop winds moderate SW. Treeline temperatures near -5. Freezing levels 1100-1300 m. Saturday: Light snow in the am, moderate amounts in the evening. Freezing levels 1300 m.
Avalanche Summary
On Monday/Tuesday the region saw a widespread natural avalanche cycle in response to snow, wind and warming. Operators are reporting numerous size 1-3.5 natural avalanches, starting in the alpine on all aspects, and running full path. Rider triggered slabs were also reported in the size 1-2 range, failing on storm snow weaknesses. There are still reports of remotely triggered avalanches up to size 2.5 on suspected mid-February SH interface. The region has seen a widespread cycle since last Saturday. With more snow and wind in the forecast the avalanche danger will elevate. This could be the story for all elevations.
Snowpack Summary
The weekend past, up to 80 cm of storm snow fell. Strong winds from the SW and fluctuating temperatures were the perfect recipe for storm slab, and wind slab instabilities. This new snow has buried variable old surfaces (surface hoar, facets, and crusts) that formed mid-February. These persistent weak layers have remained touchy all week and are a key concern at all elevations. If triggered, the avalanches will be larger than expected. Sunny, clear skies are likely to exist through Thursday. Moist-wet snow surfaces, snowballing, and point release (loose wet slides started from a point, gathering mass in a fan-like shape) are indicators of a deteriorating upper snowpack. I'd be weary of south facing slopes, affected by solar radiation. There may even be step-down potential on deeply buried weak layers. Large cornices have formed and loom as potential triggers on the slopes below.
swerner,
Avalanche Canada
