Banff Yoho & Kootenay National Park Avalanche Forecast
Apr 30th, 2019 4:00PM
Although we are well into spring, persistent problems continue to plague the snowpack. Tuesday we observed two large avalanches on this layer.
Daily convective buildup is forecasted for the remainder of the week. Morning will likely have more stable weather and as the day progresses expect to see small storm cells roll through bringing wind and precipe. We should see a warming trend into the weekend with valley temps reaching plus ten by Friday.
Up to 40cm of snow fell over the weekend at higher elevations. Strong winds during the storm have redistributed much of new snow at higher elevations. Cooler temps have promoted faceting in the upper snowpack creating a persistent interface where the new snow overlays previous crusts. Be cautious in areas where newly form slab overlays a crust.
Our field team today observed two large avalanches (size2/2.5) in the Observation Peak area. Both avalanches released from south west aspects in the alpine. The slabs where remotely triggered by skiers and initiated on the persistent problem. Although no other avalanches were observed today, the persistent problem was certainly active in this area.
This instability continues to rear its ugly head in areas where a slab sits over previously formed crusts. Though not widespread, where this layer dose exist expect it to be reactive. Tuesday we observed to large avalanches fail on this layer.
- Dig down to find and test weak layers before committing to a line.
LikelihoodLikely - Possible
Expected Size1 - 2.5
Up to 40 cm from the weekends storm coupled with strong to moderate wind has formed a slab over a variety of old wind slabs, crusts and facets in the alpine. The likelihood of avalanches is on the way down, but will persist for a few more days.
- Use caution in lee areas. Wind loading could create slabs.
- The new snow will require several days to settle and stabilize.
LikelihoodPossible - Unlikely
Expected Size1 - 2
Valid until: May 1st, 2019 4:00PM