Avalanche Forecast

High - We have a good understanding of the snowpack structure and confidence in the weather forecast

Thursday Night: Mostly cloudy. 0-5 cm of snow expected, possibly up to 15 cm around Kootenay Pass due to localized convective snowfall. Light northwest wind. Freezing level around 1250 m. Alpine low around -5 °C.

Friday: Partly cloudy. Possible trace of snow expected. Light northwest wind. Freezing level rising to 1500 m. Alpine high around -3 °C.

Saturday: Mostly Sunny. No new snow expected. Light variable wind. Freezing level at valley bottom overnight, rising to 1250 m through the day. 

Sunday: Sunny. No new snow expected. Light Northeast wind. Freezing level at valley bottom overnight, rising to 1250 m through the day. 

On Thursday, south of Nelson, avalanche control with explosives triggered several small to large avalanches, failing below through the crust that formed on Wednesday.

On Wednesday, several natural and explosive triggered storm slabs up to size 2 were reported across the region. Also, a professional operation west of Trail reported a large natural loose wet avalanche below tree line that scoured to ground, and ran to the end of the path, 550 m long. 

On Tuesday explosives control triggered large slab avalanches in the size 2-3 range. Although visibility was poor a widespread cycle of natural storm slabs in the size 2-2.5 range was also evident. There was a remote triggered size 1.5 avalanche reported in the east of the region as well. Some loose wet activity and pinwheeling was also reported at lower elevations.

On Monday there were various reports of natural and rider-triggered avalanches in the size 1-2 range, some with surprising propagation.

Snowfall continues, with 5-20 cm of new snow falling on a 1-5cm rain crust that goes as high as 2200 m in some parts of the region. There are a few great Mountain Information Network posts that describe the challenging backcountry travel conditions on Thursday due to this crust. 

Some places in the Kootenay boundary have received over 60 mm of water from this system. That has translated to about 20-60 cm (depending on elevation) of heavy, upside-down type snow. This recent storm snow sits on top of sun crusts on south-facing terrain, freezing rain crusts, old wind-pressed snow, and even some feathery surface hoar crystals in some locations. Moderate to strong southwest winds have likely contributed to cornice growth and some wind loading as well.

Weak layers from mid-February and late January made up of crusts and/or surface hoar crystals can be found around 60-70 cm deep. There are not a lot of recent avalanches on these layers, but they are still on the radar of operators in the area.

• If you are increasing your exposure to avalanche terrain, do it gradually as you gather information.
• Use small low consequence slopes to test the bond of the new snow.
• Be alert to conditions that change with elevation.
• Storm slabs in motion may step down to deeper layers resulting in large avalanches.