Avalanche Forecast
Issued: Apr 19th, 2018 4:42PM
The alpine rating is Loose Wet, Cornices and Wind Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeSummary
Confidence
Moderate -
Weather Forecast
Friday: A mix of sun and cloud with isolated wet flurries, cooling and increasing overnight. Light southwest winds. Freezing level to 2300 metres with alpine high temperatures around 0. Saturday: Cloudy with continuing flurries bringing 5-10 cm of new snow. Moderate to strong southwest winds. Freezing level to 1800 metres with alpine high temperatures around -2.Sunday: A mix of sun and cloud. Light west winds. Freezing level to 1900 metres with alpine high temperatures around -2.
Avalanche Summary
Reports from from Wednesday included an observation of a natural size 3 slab release that is believed to have released over a persistent weak layer, potentially from mid-March. Evidence of the release was seen from a distance in the Dogtooth range. Elsewhere in the north of the region, explosives control yielded several wind slabs, storm slab, and cornice releases, generally to size 2, with a couple of size 2.5. One size 3 deep persistent slab was also reported.Reports from Tuesday included several observations of large (size 2) natural storm slab releases focused around steep features below ridgetop.Poor visibility limited observations of avalanche activity on Monday.On Sunday there was a report of a near miss for skiers who triggered a size 2 wind slab on a north aspect at treeline in the northern part of the region. The northwestern part of the region saw a warming-induced natural avalanche cycle up to size 3 on large alpine features in the recent storm snow.Looking forward, continued warm temperatures will be maintaining chances of loose wet avalanche activity as well as testing the strength of storm slabs and wind slabs formed in the wake of recent snowfall and wind events.
Snowpack Summary
Generally 30-40 cm of rapidly settling storm snow overlies a crust on all aspects to at least 2000 m (and possibly higher on south-facing slopes), with up to 80 cm observed in some areas in the northwest of the region. Within this storm snow there are several buried crusts with the mostly recently buried (down about 20 cm) becoming a diminishing concern as warm temperatures promote settlement and bonding in the upper snowpack.With warm daytime temperatures and poor overnight recovery of cold temperatures, there remains some lingering concern around the mid-March persistent weak layer in the alpine where it is found 60 to 100 cm below the surface. This buried crust/surface hoar interface is likely trending towards dormancy, but should be kept in the back of our minds for its capability to produce large avalanches should it be triggered with a heavy load, such as a cornice collapse.Deeper persistent weak layers from December and January are considered dormant at this time.
Problems
Loose Wet
Aspects: North, North East, East, South East, South.
Elevations: All elevations.
Likelihood
Expected Size
Cornices
Aspects: North, North East, East, South East.
Elevations: Alpine.
Likelihood
Expected Size
Wind Slabs
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Apr 20th, 2018 2:00PM