Avalanche Forecast

Issued: Mar 3rd, 2016 8:09AM

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

rbuhler, Avalanche Canada

South Rockies.

Recently formed wind slabs are expected to remain reactive to human-triggering in exposed alpine terrain.Extra caution is required around cornices and on steep sun exposed slopes during the heat of the afternoon.

Summary

Confidence

Moderate - Timing or intensity of solar radiation is uncertain

Weather Forecast

Mostly sunny conditions are expected on Friday with moderate to strong southwest winds in the alpine and freezing levels reaching over 2000m in the afternoon. A mix of sun and cloud is forecast for Saturday with strong southwest winds in the alpine and freezing levels reaching around 2300m. A weak storm pulse is currently forecasted for Sunday morning but is only expected to bring a couple millimeters of precipitation.

Avalanche Summary

On Wednesday, two natural size 1.5 storm slabs were reported from the north of the region. These were 30cm thick and released on an southeast-east aspect in the alpine. A natural size 1.5 loose dry avalanche was also reported in the north from an east aspect gully feature in the alpine. In the southeast of the region, several size 1 wind slabs were ski cut on north through east aspects at 1800-2100m elevation. These were 10-30cm thick on steep leeward features around ridge crests.

Snowpack Summary

15-25cm of recent storm snow with strong southwest winds have formed wind slabs in leeward features.Â The recent snowfall may overlie a sun crust on steep solar aspects or small surface hoar in isolated sheltered areas. The recent wind has also formed large cornices which are expected to become weak with the forecast warming and sun. Old weak layers can still be found in the snowpack but these layers are reported to be well bonded and triggering has become unlikely.

Problems

Wind Slabs

Recently formed wind slabs are expected to be reactive to human-triggering. Ongoing winds will continue to load leeward features. In deeper snowfall areas in the northwest, a more widespread storm slab problem may exist.

Avoid freshly wind loaded features.>Travel on ridgetops to avoid wind slabs on slopes below.>

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Cornices

Cornices are expected to be fragile and may fail naturally with daytime warming and sun exposure. Not only are they a hazard in themselves, but also a heavy trigger for slabs on the slope below.

Extra caution needed around cornices with current conditions.>Cornices become weak with daytime heating, so travel early on exposed slopes.>

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 3

Loose Dry

Natural sluffing is expected from steep sun exposed slopes during the heat of the afternoon.

Be cautious of sluffing in steep terrain. >Avoid steep sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet. >

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

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Mar 4th, 2016 2:00PM