Avalanche Forecast
Regions: Banff, Banff Yoho Kootenay, East Side 93N, Field, Kootenay, LLSA, Lake Louise, Sunshine, West Side 93N.
Mt. Field, Mt Dennis and Mt. Stephen avalanche closure zones are CLOSED on Wednesday, March 19th.
The sun is forecast to come out on Wednesday and this might be enough to increase the danger to HIGH. Don't expose yourself to avalanche terrain, especially if the sun is out and warming the slopes!
Confidence
Moderate
Avalanche Summary
A group digging a snowpit in low angle terrain with no overhead exposure on Observation Peak today felt a whumph that remote triggered 5-6 avalanches up to size 2.5 in the cirque around them. This remote trigger with large propagation highlights the dangerous snowpack conditions we are currently in.
Additionally, we have seen widespread avalanche activity over the last 10 days, including a fatality in the region on Friday.
Snowpack Summary
Over the past 10 days, 40-90 cm of new snow has accumulated and settled into a slab, with the deepest amounts found in the Bow Summit area and along the Wapta. This sits on a very weak, faceted mid and lower snowpack and fails easily in snowpack tests. This condition will be slow to stabilize.
Weather Summary
A ridge of high pressure is over us and will bring sun on Wednesday. Temperatures will remain seasonal, between (-1 and -10) except in the direct sun where it will warm up fast. Alpine winds will be moderate from the SW.
On Thursday, a series of systems start to move in bringing light snow. Friday we should see a bigger system with 5-10 cm forecast by Saturday AM.
Terrain and Travel Advice
- Make conservative terrain choices and avoid overhead hazard.
- Remote triggering is a big concern, be aware of the potential for wide propagations and large, destructive avalanches at all elevations.
- Loose avalanches may step down to deeper layers, resulting in larger avalanches.
Avalanche Problems
Persistent Slabs
A 40-90 cm slab overlies mid-pack facets and depth hoar at the ground. Numerous avalanches have been failing on both these layers (persistent AND deep persistent slabs) and this will not change anytime soon as these problems are slow to heal. Avoid starting zones and be very wary of overhead hazard.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Possible - Likely
Expected Size: 2 - 3.5
Loose Wet
If the sun is out, the snow will warm quickly and loose wet avalanches will start to run. These could be a trigger for the deeper layers resulting in much larger avalanches.
Aspects: South, South West, West.
Elevations: All elevations.
Likelihood: Possible
Expected Size: 1 - 2