Avalanche Forecast
Issued: Feb 13th, 2019 4:51PM
The alpine rating is Persistent Slabs and Wind Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeSummary
Confidence
High -
Weather Forecast
WEDNESDAY Night: Clear periods, light southeast wind, alpine temperature -15 C.THURSDAY: Mix of sun and cloud, light to moderate southeast wind, alpine temperature -10 C.FRIDAY: Flurries, accumulation 5-10 cm , light to moderate southwest wind, alpine temperature -7 CSATURDAY: Flurries, accumulation 5-10 cm, light north wind, alpine temperature -8 C
Avalanche Summary
Most recent avalanche activity on Monday and Tuesday has been reported as naturally triggered size 1-2 windslabs between 2000 and 2300 m on all aspects and also a few skier triggered size 1 and 2 persistent slab avalanches on northeast aspects between 1200 and 1900 m. A number of significant avalanches have occurred on persistent weak layers in this region over the last several days, making it the hotspot for human-triggered avalanches at this time.On Sunday, a size 3 slab avalanche released at 1750 m on a south aspect when a sluff stepped down to the mid-January layer. Another avalanche was remote-triggered from 80 m away on an east aspect at around 1600 m.On Saturday, a snowmobiler died in a large (size 2) slab avalanche in the Oventop Creek drainage (report here). It was triggered by the rider at 2100 m on a south aspect. The crown fracture varied from 15-100 cm deep, suggesting wind loading was a factor in the incident. Also on Saturday, a very large (size 3.5) natural avalanche released in a layer down 70 cm, apparently caused by icefall.
Snowpack Summary
There are two prominent, touchy weak layers in the snowpack that have been responsible for a several dangerous avalanches, including one fatality in this region. The upper layer was buried at the end of January and lies approximately 40 cm below the surface. The lower one was buried mid-January and lies approximately 75 cm below the surface. Both comprise a mix of surface hoar and facets and may lie on top of a sun crust on southerly aspects. Both layers are highly reactive and in any given location, one or both could potentially exist in the snowpack. Wide propagation has been noted, meaning avalanches have the potential to go big (up to size 3). These weak layers are most prevalent at treeline and below treeline elevations, but may also be found in sheltered areas in the alpine.Strong northerly and easterly winds have created complicated patterns of wind-loaded snow. Many slopes are reverse-loaded or cross-loaded.Average snow depths are approximately 300 cm. Very sporadically, failures have occurred near the base of the snowpack in or close to this region. These releases have almost all been from high alpine areas, possibly triggered close to rocky features.
Problems
Persistent Slabs
Aspects: All aspects.
Elevations: Treeline, Below Treeline.
Likelihood
Expected Size
Wind Slabs
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Feb 14th, 2019 2:00PM