Avalanche Forecast

Issued: Feb 15th, 2019 8:00AM

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

andrew jones, Parks Canada

Glacier.

Variable surface conditions exist throughout the bulletin region. Travel cautiously in flat light.

Summary

Weather Forecast

The arctic ridge continues to keep moisture from advancing northward. Mainly cloudy with isolated flurries today, with a freezing level of 1200m. Ridge winds are forecast to be light from the SW. Freezing levels are expected to lower over the weekend, with ~ 5 cm of snowfall.

Snowpack Summary

A dusting of new snow covers old hard wind slabs, and scoured surfaces in the ALP and exposed areas of TL. Cold temps have created a weak, faceted upper snowpack. Wind slabs have been most reactive on solar aspects, where crusts are buried. The Jan 17 SH is down 50-70cm at TL and below.

Avalanche Summary

On Saturday there was a natural cycle triggered by strong N-NE winds. Since the weekend we have only seen sporadic small wind slabs and loose dry up to size 2.0 in the alpine. There have been no reports of any new avalanches on the Jan17th PWL in over a week.

Confidence

Forecast snowfall amounts are uncertain

Problems

Wind Slabs

Ongoing moderate winds have created widespread wind affect in the Alpine and exposed areas at Tree Line, making for challenging travel. Windslabs vary from supportive hard slabs to pockets of wind-loaded facets.

Be careful with wind loaded pockets, especially near ridge crests and roll-overs.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Persistent Slabs

The Jan 17 Surface Hoar layer is buried 50 to 70cm at and below tree line. This interface exists on all aspects and most reactive between 1400-1900m, especially on steep solar aspects where it overlies a crust.

Use caution on open slopes and convex rolls at treeline where buried surface hoar may be preserved.Watch for whumpfing, hollow sounds, and shooting cracks.

Aspects: All aspects.

Elevations: Treeline, Below Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Valid until: Feb 16th, 2019 8:00AM