Avalanche Forecast

Issued: Apr 3rd, 2015 10:12AM

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

jlammers, Avalanche Canada

South Rockies.

Snowpack and avalanche observations are becoming scarce. If you've been in the backcountry, please tell us what you've seen via the Mountain Information Network. For more details, click here.

Summary

Confidence

Fair - Intensity of incoming weather systems is uncertain on Saturday

Weather Forecast

On Saturday, expect light snowfall (up to 5cm). On Sunday, we should see a mix of sun and cloud. Up to 10cm of snow is forecast for Monday with highest accumulations falling in the south of the region. Ridgetop winds should be moderate from the southwest with Saturday's pulse, becoming light for the rest of the period. Daytime freezing levels should remain at about 1600m.

Avalanche Summary

We have had no recent reports of avalanche activity.

Snowpack Summary

Observations have been extremely limited, although I expect light amounts of low-density snow overlie a widespread and supportive melt-freeze crust,. Gusty winds may have redistributed the surface snow resulting in wind slab formation in the alpine. The mid-March rain crust is down 35 to 70cm and has shown a good bond with snow above. Old persistent weak layers are still intact in the mid and lower snowpack and there may be potential for these layers to wake up with a big cornice fall, sustained warming and/or a significant rain event.

Problems

Wind Slabs

Light snowfall and moderate southwest winds are forecast to form new wind slabs in exposed higher elevation terrain. Watch for triggering in the lee of ridge crests and in gullies.

Travel on ridgetops to avoid wind slabs on slopes below, but be careful with cornices!>Be careful with wind loaded pockets, especially near ridge crests and roll-overs.>

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Possible - Likely

Expected Size

1 - 2

Cornices

Large cornices exist at ridge top, and may fail under the weight of a rider. As spring conditions evolve, remember that destructive cornice falls become more likely during periods of warming and solar radiation.

Give cornices a wide berth when traveling on or below ridges. Remember that cornices become weak with daytime heating.>

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

Elevations: Alpine.

Likelihood

Possible - Likely

Expected Size

1 - 4

Valid until: Apr 4th, 2015 2:00PM