Avalanche Forecast

Issued: Mar 13th, 2018 4:00PM

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

landon shepherd, Parks Canada

Jasper.

Highway 93 south of Jasper to Saskatchewan crossing and the Maligne road remain closed for avalanche control

Summary

Weather Forecast

Strong high pressure with southern warm air will continue to Wednesday evening with freezing levels close to 3000m and strong solar effect throughout the forecast zone. Wednesday night/Thursday brings cloud cover and more seasonable temperatures with light flurries, a change that persists into the weekend.

Snowpack Summary

Our structurally weak snowpack is slowly warming under spring-like temps and strong solar radiation. Settlement and sintering is occurring in the upper snowpack with warmer temps and melt-freeze crusts forming on steep solar slopes. Mid and lower snowpack weaknesses persist but tend to be reactive only on alpine solar facing slopes.

Avalanche Summary

Warm temps and rising freezing levels are resulting in loose dry avalanches at upper elevations and loose wet avalanches on solar slopes below treeline. Avalanches below treeline are to size 2. Alpine slopes have also released as slabs to midpack and have entrained snow up to size 2.5, but have potential to size 3.

Confidence

Due to the number and quality of field observations

Problems

Loose Wet

solar aspects and elevations below the freezing level

Minimize exposure to steep, sun exposed slopes when the solar radiation is strong.Cornices become weak with daytime heating.

Aspects: North, North East, East, South East, South.

Elevations: Alpine, Treeline.

Likelihood

Likely - Very Likely

Expected Size

1 - 2.5

Loose Dry

More shaded aspects and elevations above the freezing level.

Avoid ice climbs that are in terrain traps below large start zones.

Aspects: North, North East, East, South East.

Elevations: Alpine, Treeline.

Likelihood

Very Likely

Expected Size

1 - 2.5

Persistent Slabs

Rising freezing levels and large triggers like smaller avalanches may wake up deeper slab instabilities

Be wary of large alpine slopes that did not previously avalanche.

Aspects: North, North East, East, South East, South, South West.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1.5 - 3

Valid until: Mar 14th, 2018 4:00PM