As the freezing level falls overnight and then warms during the afternoon, you will find that conditions change rapidly through the day. Be cognizant that daytime warming can rapidly destabilize the upper snowpack.
Prepare to continually evaluate the conditions, and change plans as necessary.
Strong southwest winds at high elevations could be building deeper, more reactive pockets of slab in leeward terrain.
Use extra caution around ridgecrests, rolls, and on convex slopes. Retreat to mellower terrain if you find signs of instability like shooting cracks, whumpfs, or recent avalanches.
A very wet storm has soaked the surface snow, and while freezing levels overnight are falling, a loose wet avalanche problem may remerge as daytime temperatures warm. Expect the upper snowpack to rapidly become unconsolidated when the sun appears even if it just for a brief period.
Watch for signs of loose wet instability, like snow pinwheeling or snowballing down the slope, or surface snow that starts to look and feel like a slurpy.
On Monday and Tuesday, in the Fernie area. Warming and rain induced a widespread, naturally triggered, loose wet avalanche cycle. This included several large (size 2-2.5), avalanches and one large (size 2.5) glide slab.
On Saturday, south of Fernie, a large (size 2), rider triggered avalanche was reported on a NE/E facing slope around treeline. The reporting riders kindly shared their close call on the Mountain Information Network (MIN). See the post here for more information and photos. Based on the direction the cornices have formed on the ridge above, it looks like the feature may have been cross-loaded by the wind. The reporting party said it appeared to trigger on a thin spot near some rocks, and that warm temperatures and sun may have been a factor.
If you head out in the backcountry, let us know what you are seeing by submitting a report to the Mountain Information Network.
Overnight cooling has consolidated and the saturated surface snow from the past warm and wet storm event. Most weather reports indicate 20-30 mm of precipitation fell mostly in the form of rain.
The mid-snowpack is generally well-settled and strong.
At treeline and below, shallow snowpack areas are likely to be isothermal. Rain-soaked surfaces are starting to freeze as temperatures drop, and a lot more dirt is showing at low elevations.
The lower snowpack includes a layer of weak sugary crystals near the ground. This layer has not produced recent avalanche activity in this area, but professionals continue to monitor for signs of it becoming active.
Unsettled and convective weather continues. This unsettled weather will bring brief but intense periods of snowfall and pinpointing the location of these localized events creates a high level of uncertainty with this weather forecast. Prepare to continually evaluate the conditions, and change plans as necessary.
Wednesday Night
Clearing with cloudy periods. 1-5 cm of snow is possible in the alpine. Freezing level descending to valley bottom, Alpine temperature low of -10°C. Light southwest ridgetop wind.
Thursday
Clear and sunny with 5-10 cm of snow possible in the alpine. Freezing level rising to 1500m mid day. Alpine temperature high of -1. Light southwest wind.
Friday
Clear and sunny with with possible trace amounts of snowfall. Freezing level rising to 1750m mid day. Alpine temperature high of 1°C. Light to moderate southwest wind.
Saturday
Clear and sunny with no forecast precipitation. Freezing level rising to 2000m mid day. Alpine temperature high of 2°C. Light to moderate southwest wind.
More details can be found in the Mountain Weather Forecast.
