Avalanche Forecast

Issued: Jan 25th, 2019 3:55PM

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

Sea To Sky.

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 3000 m.SATURDAY: Clear skies, light northwest winds, alpine temperature between 3 C and 6 C, freezing level 3200 m with inversion conditions.SUNDAY: Clear skies, moderate northwest winds, alpine temperature between -1 C and 2 C, freezing level dropping from 2500 m to 2000 m over the day.MONDAY: Clear skies, light north winds, alpine temperature -3 C, freezing level 1000 m.

Avalanche Summary

Wet loose avalanches were observed on southerly aspects on Thursday. The likelihood of these avalanches should increase with warm air temperatures invading the province.

Snowpack Summary

The snow surface may moisten with warm air temperatures on all aspects, but most pronounced on southerly aspects. Beneath this, around 40 to 60 cm of snow sits on a sun crust on south aspects and weak and feathery surface hoar in sheltered and shaded areas. The surface hoar is likely most pronounced at treeline and upper below treeline elevations.The remainder of the snowpack is generally well-settled.

Problems

Persistent Slabs

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

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

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

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.

Watch for clues that the snowpack is warming up, like moist snow or sluffing off of cliffs.Use caution above cliffs where small avalanches may have severe consequences.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