Avalanche Forecast
Issued: Apr 9th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs, Loose Wet and Deep Persistent Slabs.
MH,
Avalanche Canada
A spring storm is upon us, bringing up to 40cm to the Alpine and rain to lower elevations. Expect wild variability as you transition through elevation bands, from wet heavy slop to dry fluff and dense slab.
Be conservative in your terrain choices... your best option may be to slide into that neon onesie and shred laps at your local ski resort until your quads explode.
Summary
Confidence
Avalanche Summary
On Sunday a group remotely triggered the glacier roll, adjacent to the Cleaver, from below. The last person in the group of 4 was caught and carried for ~50m. They were partially buried, sustained a broken leg and lost some equipment.
As the storm continues, avalanche activity is expected to increase Sunday night into Monday.
Snowpack Summary
~25cm of new snow expected in the alpine will bring the weekly total to ~60cm, with 5-10cm of wet snow at the valley bottom.
The March 31 interface is buried ~60cm down and consists of a crust on solar aspects and a facet/surface hoar combo on polar aspects.
The snowpack is generally strong. However, the basal weakness from November can still be found near the ground in many locations. It may be possible for this layer to become active during this storm cycle.
Weather Summary
Spring pow continues with up to 20cm of new snow by Monday morning and another 15-20cm by Tuesday morning. The new snow is accompanied by strong SW winds, 30-70km/hr. Freezing levels may rise up to ~2200m with an alpine high of -2.
By Wednesday, the temps will drop, winds will decrease and any chance of new snow will dissipate.
Terrain and Travel Advice
- Potential for wide propagation exists, fresh slabs may rest on surface hoar, facets and/or crust.
- If triggered loose wet avalanches may step down to deeper layers resulting in larger avalanches.
- The more the snow feels like a slurpy, the more likely loose wet avalanches will become.
- In areas where deep persistent slabs may exist, avoid shallow or variable depth snowpacks and unsupported terrain features.
Problems
Storm Slabs
New snow and strong SW winds overnight and into Monday will build fresh storm slabs. Expect these slabs to be deeper and potentially more reactive on lee, wind loaded slopes. The increasing slab buries a crust on solar aspects and facets and surface hoar on polar aspects.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Loose Wet
Freezing levels may reach as high as 2200m dropping up to 40mm of precipitation (some of it falling as rain) over the next two days. The overnight crust recovery has been poor, only reaching -2 at treeline and remaining at 0 at valley bottom.
Aspects: All aspects.
Elevations: Treeline, Below Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
We are bringing the Deep Persistent problem back due to the incoming storm and rise in freezing levels. There has been no activity on this layer for several weeks, but it's uncertain what will be enough to re-activate this layer.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Apr 10th, 2023 4:00PM
