http://www.pc.gc.ca/apps/scond/Cond_E.asp?oID=30469&oPark=100205Human triggered avalanches are likely. Expect avalanche activity to increase throughout the day as the warm temps and sun begin to affect the snowpack.
Weather Forecast
The valley cloud is expected to linger until midday, once above it you will be treated to mainly sunny skies. There will be a slight temperature inversion with the alpine reaching a high of +2 with 20 km/hr south east winds. This is the first day of a two day warming period. No snow in the forecast until Tuesday evening once temps drop.
Snowpack Summary
70cm of snow over the past week has settled into a slab over several weak layers. Jan 4th surface hoar is down ~60cm and the Dec 15 surface hoar persistent weak layer is down around 100cm. The recent snow load has made these layers reactive with sudden planar results showing high propagation potential.
Avalanche Summary
Several sz 1.5 - 2.5 avalanches and one sz 3.0 avalanche from steep, aggressive terrain along the highway corridor yesterday.Consistent reports of whumphing and shooting cracks since the storm early last week.Hard Sudden Planar (SP) results down ~60cm on the Jan 4 surface hoar (5mm) during stability tests yesterday.
Problems
Persistent Slabs
Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.
Persistent Slabs
Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.