Archived

Avalanche Forecast

Dec 6th, 2018–Dec 7th, 2018

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Regions: Lizard-Flathead.

Triggering a persistent slab avalanche remains a possibility, especially in steep unsupported alpine features.

Confidence

Moderate - Due to the number of field observations

Weather Forecast

This benign blocking pattern will be with us for the foreseeable future. Things begin to change on the Coast this weekend, but no precipitation is expected to make it to the Lizard Range.THURSDAY NIGHT: Freezing level at valley bottom, light northwest wind, no significant precipitation.FRIDAY: Local valley cloud, alpine high temperatures around -10 C, light to moderate wind out of the west, no significant precipitation.SATURDAY: Scattered cloud cover, alpine high temperatures around -10 C, light wind out of the west, no significant precipitation.SUNDAY: Scattered cloud cover, alpine high temperatures around -8 C, moderate to strong wind out of the southwest, no significant precipitation.

Avalanche Summary

A few small wind slabs (size 1) were reported in the Lizard Range on Thursday, and a few small loose dry avalanches were reported from steep alpine features on Wednesday.On Sunday a human triggered avalanche was reported in Cornice Bowl north of Fernie. It occurred on a northwest facing feature at 2300 m and produced a size 2 avalanche that ran on the early November crust. The crown was 30 to 40 cm deep, approximately 20 m wide and 300 m in length. There are good photos in this MIN report.If you're in the backcountry and have observations to share, please post to the Mountain Information Network (MIN).

Snowpack Summary

It's thin out there, check out the MIN report from our field team on Wednesday. At treeline the average snowpack depth is about 80 cm, with only thin coverage at lower elevations. There is a great MIN Report here that provides a visual representation of the current snowpack.30-50 cm of recent low density snow sits on a combination of crust and surface hoar. The crust is most prevalent at and above treeline and is likely most problematic on north-facing features, especially those that are large and planar in nature. The surface hoar is tricky to pin down because it is quite spotty in distribution, but it appears to be most prevalent on sheltered slopes at and above treeline. At the bottom of the snowpack lies another crust with weak sugary facets around it.

Avalanche Problems

Persistent Slabs

30-50 cm of old snow is sitting above buried weak layers composed of crusts and/or surface hoar.

Be aware of the potential for large avalanches due to the presence of a persistent slab.Back off if you encounter signs of instability like whumphing, shooting cracks or recent avalanches.Avoid shallow, rocky areas where the snowpack transitions from thick to thin.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Unlikely - Possible

Expected Size: 1 - 2