Avalanche Forecast

Fair - Timing, track, or intensity of incoming weather is uncertain on Sunday

The next couple days brings cooler temperatures and dryer conditions. Friday: Snow amounts up to 5cms in the morning. Mix of sun and cloud in the afternoon. Ridgetop winds 20-30km/hr from the SW. Alpine temperatures near -6, and treeline temperatures near -4. Freezing levels at valley bottom. Saturday: A Northerly flow brings mainly sunny skies with seasonal conditions. Ridgetop winds 15-20km/hr from the NW. Treeline temperatures near -9. Sunday: Light to moderate precipitation is expected accompanied by strong SW winds. Freezing levels may rise to 2000m by the afternoon.

Thursday morning a large natural cycle was reported in the Rogers Pass area. These were large avalanches up to size 3.5 running to the end of run out zones and into creeks. Outside of the Rogers Pass area several natural avalanches occurred around 2400m on S-W aspects. Also to note a natural cornice release triggered a size 2 slab on the slope below. The mid-December persistent weak layer is buried down 80-120cms and is still a layer of concern. Avalanches that are failing on this layer are large-very large (sz 2-3.5). As the natural activity has somewhat tapered off, the sensitivity to skier, or sledder triggers are likely.

New snow up to 20cms has fallen over the region. This blankets treeline and alpine elevations and buries a new surface hoar layer (up to 10mm in size) that formed over the New Year. Wind slabs are widespread and found in exposed alpine and treeline locations. With warmer temperatures the new snow has set up into a slab that overlies the surface hoar and old wind slabs. We can expect a rain crust up to 1700m due to Wednesday's precipitation and high freezing levels. Below the surface 80-120cms lurks a surface hoar/facet/crust interface (persistent weak layer) from mid-December. Testing on this layer has shown moderate to hard results with sudden planer characteristics. This weak layer has been very reactive; producing large, destructive avalanches. It still remains a layer of concern and should continue to be on your radar. Below this layer sits a strong mid pack.