Avalanche Forecast
Issued: Mar 1st, 2018 3:08PM
The alpine rating is Storm Slabs and Persistent Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeSummary
Confidence
Moderate - Intensity of incoming weather systems is uncertain
Weather Forecast
A weak front is stalling on a north to south axis over the region setting up a southerly wind with most snow expected in the southern parts of the region.Friday: The important part of the weather forecast is new snow and wind overnight Thursday: only up to 10cm new snow is expected but moderate south or southeast winds will blow it around. Calmer and drier through the day. Temperatures staying on the negative side of zero. Mix of sun and cloud, most sun in the north.Saturday:Â Mix of sun and cloud (sunnier in north, cloudier in south) but dry with only flurries. Little wind at all elevations and temperatures at treeline staying around or below -5 C.Sunday: Compared to Saturday, Sunday looks very similar:Â maybe a little bit sunnier and continued dry. It might be a bit windier (light from the SW), and similar temperatures.
Avalanche Summary
Wednesday reports either spoke to "no new avalanches" or small (size 1 to 2) slabs triggered by people. There was a single size 2.5 avalanche on a south aspect releasing on a layer approximately 70 cm deep.Prior to Wednesday, avalanche activity consisted of mainly loose dry sluffing, storm slabs, or wind slabs (skier triggered and skier remote) in the size 1to 2 range. However, we've received reports of persistent slab avalanches where recent accumulations have been the highest. These avalanches, were remotely triggered (from a distance) or naturally occurring. We suspect the sun crust buried mid-February is the culprit for those on southerly aspects. Deep persistent avalanche activity has become less frequent over the past week.
Snowpack Summary
The 30 to 50cm of recent storm snow is "right side up" and settling. Earlier in the last storm it was redistributed into localized wind slabs. It covers old surfaces including faceted powder, a sun crust on solar aspects, and surface hoar on shady slopes. Around 50 to 80cm below the surface there's a layer buried mid-February that's a sun crust on solar aspects and spotty surface hoar on sheltered slopes. This layer looks most concerning on solar aspects where it's associated with with small facets or surface hoar. March 01 today -- 'tis the season when solar aspects start to get complicated!There are several deeper layers that have shown signs of improving but still remain suspect as low probability - high consequence avalanche problems. I'm talking about surface hoar layer buried back in December and January. Near the base of the snowpack is a November crust combined with loose sugary snow. These layers may "wake-up" with strong inputs such as sustained warming, sustained snowfall, large triggers (e.g. cornice fall, smaller avalanches coming down from above); human triggering is also possible in shallow, rocky terrain.
Problems
Storm Slabs
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Persistent Slabs
Aspects: North, North East, East, South East, South.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Mar 2nd, 2018 2:00PM