Avalanche Forecast

Issued: Mar 28th, 2015 8:00AM

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.

Parks Canada andrew jones, Parks Canada

Avalanche hazard will increase with warm temperatures and sunshine. Persistent layers in the upper snowpack are sensitive to triggering.

Summary

Weather Forecast

Freezing levels remained high overnight but are expected to drop to 2000m today.  Precipitation will taper off later this morning with a mix of sun and cloud.  Expect moderate westerly ridge winds with gusts to 55km/hr and an alpine high of  0 C. Typical spring temperatures resume tonight as freezing levels drop to 1400m.12 cm of snow for Sunday.

Snowpack Summary

Freezing levels above 2200m overnight and 10mm of rain early this morning. Suspect moist and warm upper snowpack. Lee loading from strong S winds. At higher elevations, up to 70cm of settling storm snow sits over several persistent week layers in the form of crusts, surface hoar and facetted layers which are reactive to light loads such as skiers.

Avalanche Summary

Artillery avalanche control in the highway corridor resulted in several size 20-2.5 slab avalanches. Avalanches were moist in character and failed on a crust in the upper snowpack. Several Natural loose wet and slab avalanches were observed in the highway corridor and adjacent backcountry areas during the warmest part to the day.

Confidence

Freezing levels are uncertain

Problems

Persistent Slabs

An icon showing Persistent Slabs
Layers down 40-100cm have been triggered naturally and by light loads such as skiers and sluffing from steep terrain. Remote triggering and wide propagations are possible. Cornice failures from warm daytime temperatures could trigger these layers.
Be aware of the potential for wide propagations.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

2 - 3

Loose Wet

An icon showing Loose Wet
Warm temperatures prevented a re-freeze of surface snow. 10mm of rain fell this morning, further destabilizing the upper snowpack. Freezing levels at 2000m and sunshine will increase hazard on solar slopes. These avalanches can run far and fast.
Watch for clues, like sluffing off of cliffs, that the snowpack is warming up.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely - Very Likely

Expected Size

1 - 2

Valid until: Mar 29th, 2015 8:00AM