Avalanche Forecast

Moderate - Uncertainty is due to rapidly fluctuating freezing levels.

Warm air from the incoming front will ride on top of colder air, making for a wide variety of freezing levels across the region for Friday.

 

THURSDAY NIGHT: Mostly clear. No new snow expected. Moderate northwest wind. Freezing level at valley bottom. Alpine low around -7 C.

FRIDAY: Partly cloudy. No new snow expected. Moderate to strong west wind. Possible above freezing layer making for temperatures above 0 C between 1500 and 2000 m in the southern end of the region. 

SATURDAY: Partly cloudy. 0-5 cm of snow expected overnight and 0-5 cm through the day. Strong west wind. Possible above freezing layer making for temperatures above 0 C between 1500 and 2000 m in the southern end of the region. 

SUNDAY: Mostly cloudy. No new snow expected. Light southeast wind. Above freezing layer breaking down, freezing levels around 600 m.

On Thursday, our field team was riding in the Microwave area, and saw one large wet loose avalanche around treeline that likely occured on Wednesday.

On Wednesday, a professional operation northeast of Hazelton reported several small, rider triggered avalanches, both loose wet, and storm slab. Additionally, a professional operation in the Howson mountain range reported numerous natural loose wet, wet slab, and glide slab avalanches up to size 2.5. A few operations reported bad visibility and bad weather stopping them from gathering information.

Below 2000 m (1000 m in the north end of the region), 10-30 mm of rain fell throughout the day on Wednesday, soaking the upper snowpack. In most places, a firm crust has formed on the surface. At treeline, this crust may be supportive to skis and snowshoes, but breakable under a snowmobile or a boot. Below treeline, the crust is thinner, weaker, and overlies moist snow.

Above 2000 m in the southern end of the region there are areas that received up to 30cm of snow, but observations so far suggest that this terrain was hammered by the wind, scouring some terrain and forming unreactive wind effected surfaces elsewhere.

See here for a summary of the conditions in the Microwave area from our field team.

In the northern end of the region, where there was still dry snow available for transport, Thursday's wind formed reactive windslabs in the alpine. 

In some areas a combination of two thin crusts with faceting above and below exists 40 to 50 cm deep. Deeper in the snowpack, two weak layers may exist around 60 to 120 cm deep. The first is a surface hoar layer from mid-January and the second is a layer of faceted snow from early January. These layers haven't produced recent avalanches, but they are producing concerning results in snowpack tests, and the potential remains until these layers bond to the snowpack.

• When a thick, melt-freeze surface crust is present, avalanche activity is unlikely.
• A crust on the surface will help bind the snow together, but may make for tough travel conditions.
• Be alert to conditions that change with elevation and sun exposure.
• Although their spatial distribution is isolated, wind slabs are reactive.
• Recent wind has varied in direction so watch for wind slabs on all aspects.