Avalanche Forecast

Issued: Jan 25th, 2019 3:59PM

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

mconlan, Avalanche Canada

South Coast Inland.

Warm air and sunny skies will influence the snowpack on Saturday. The amount of warming is uncertain; expect the most warming on south aspects and for the snowpack to possibly moisten on other aspects too. This may make the snow very touchy.

Summary

Confidence

Moderate - Freezing levels are uncertain

Weather Forecast

FRIDAY NIGHT: Clear skies, freezing level rising to 2700 m.SATURDAY: Clear skies, light northwest winds, alpine temperature between 2 C and 6 C, freezing level 3000 m with inversion conditions.SUNDAY: Clear skies, moderate northwest winds, alpine temperature near -1 C, freezing level dropping from 2000 m to 1000 m over the day.MONDAY: Clear skies, light north winds, alpine temperature -7 C, freezing level below valley bottom.

Avalanche Summary

The surface hoar buried 30 to 60 cm has been reactive to skier traffic in the past few days. Check out recent avalanche reports in the MIN, here and here.Looking towards the weekend, the likelihood of triggering the layers discussed in the Snowpack Summary may increase. Also expect loose wet avalanches if the air temperatures reach as warm as the weather forecast predicts.

Snowpack Summary

Warm air temperatures are entering the region and may moisten the snow surface at all elevations and on all aspects, but most pronounced on south aspects. Beneath this, around 30 to 60 cm of snow sits on a sun crust on southerly aspects, a temperature crust below around 1700 m on all aspects, and feathery surface hoar in areas sheltered by the wind at all elevation bands. The surface hoar may be most pronounced on west, north, and east aspects below 2100 m. This layer may be touchy to human traffic this weekend.Below this, the snowpack is generally well-settled. In certain parts of the region, you may still find a weak layer of surface hoar buried about 60 to 120 cm in sheltered areas around treeline. There havenâ€™t been any recent avalanches on this layer but the likelihood of triggering it may increase this weekend with warm air temperatures.

Problems

Persistent Slabs

Around 30 to 60 cm of snow sits above a weak layer of surface hoar and variable crusts. The warm air may make it more likely to initiate an avalanche on these layers. Treating this snow with caution is advised.

Avoid steep slopes on warm or sunny days.Watch for signs of instability such as whumpfing, cracking, or recent avalanches.Pay attention to overhead hazards like cornices, which could easily trigger persistent slabs.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2

Loose Wet

Warm air and sun will likely moisten the snow surface. If this occurs, expect natural loose wet avalanches and for them to be touchy to human traffic. This will likely be most pronounced on southerly aspects.

Use caution above cliffs where small avalanches may have severe consequences.Watch for clues that the snowpack is warming up, like moist snow or sluffing off of cliffs.Avoid sun-exposed slopes when the solar radiation is strong, especially if snow is moist or wet.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

1 - 1.5

Valid until: Jan 26th, 2019 2:00PM