Avalanche Forecast

Issued: Mar 19th, 2019 4:32PM

The alpine rating is high, the treeline rating is high, and the below treeline rating is high. Known problems include Loose Wet and Persistent Slabs.

mconlan, Avalanche Canada

South Columbia.

The hot and sunny weather persists on Wednesday, which will likely continue the natural avalanche cycle. The danger will be the highest when the day heats up, so make sure you are completely out of avalanche terrain, with no overhead exposure.

Summary

Confidence

High -

Weather Forecast

TUESDAY NIGHT: Clear skies, light southeast wind, alpine temperature 6 C, freezing level 3200 m.WEDNESDAY: Clear skies, light southeast wind, alpine temperature 6 C, freezing level 3300 m.THURSDAY: Clear skies, light southeast wind, alpine temperature 5 C, freezing level 2900 m.FRIDAY: Partly cloudy skies, light south wind, alpine temperature 4 C, freezing level 2700 m.

Avalanche Summary

The wet loose avalanche cycle continued on Monday, producing small to large (size 1.5 to 3) avalanches on southeast to southwest aspects. The avalanches were at all elevations. There were also reports of slab avalanches around 30 to 40 cm deep, releasing on the interface described in the snowpack summary. They were on all aspects and between 1800 m and 2700 m.This avalanche cycle is expected to continue, as temperatures remain exceptionally warm and the sun shines strong.

Snowpack Summary

A cohesive slab of snow around 30 to 60 cm thick overlies weak and sugary faceted snow or a melt-freeze crust on sun-exposed slopes. Natural avalanches are expected to continue at this interface.Below treeline, a weak layer of faceted grains and/or feathery surface hoar crystals buried in mid-January can be found around 60 to 120 cm deep, which may be combined with a melt-freeze crust on south aspects. The current warm conditions may awaken this layer, resulting in large, destructive avalanches. Steep cutblocks and large open glades at lower elevations are the most likely places to trigger this layer. Smaller loose wet avalanches may trigger this layer.The lower snowpack is generally consolidated and strong. The exception is around thin, rocky areas in the alpine, where the snowpack is composed of faceted snow. The warm air and sunny skies could trigger very large avalanches that could run to the valley bottom.

Problems

Loose Wet

The upper snowpack has destabilized with warm air temperature and strong sunshine, producing large avalanches (to size 3). The most problematic time is under maximum warming during afternoon hours.

Best to avoid avalanche terrain, particularly on slopes exposed to the sun.Avoid sun-exposed slopes when the solar radiation is strong.Constantly look up: avoid overhead exposure, as avalanches could run full-path.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Very Likely

Expected Size

1 - 3

Persistent Slabs

A cohesive slab is poorly bonded to weak, sugary faceted snow or a melt-freeze crust. The warm temperature and strong sun has increased the likelihood of triggering a slab avalanche by humans, cornices, and naturally.

Avalanche could reach valley bottom; avoid all overhead exposure.Avoid corniced ridges; they are weak and could trigger persistent slab avalanches.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1.5 - 3

Valid until: Mar 20th, 2019 2:00PM