Avalanche Forecast
Issued: Mar 25th, 2016 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Persistent Slabs, Cornices and Loose Wet.
tim haggarty,
Avalanche Canada
Heads Up! A Special Avalanche Warning is in effect as we do not think the danger rating of MODERATE adequately illustrates the complexity in the snowpack right now. This is a low probability, high consequence period with a highly variable snowpack.
Summary
Weather Forecast
Friday was mainly clear with a few convective flurries and strong solar input warming the snow to at least treeline on solar aspects and freezing levels reaching 2100m. Saturday looks like a carbon copy with a weak ridge approaching the divide late in the day. Expect a crisp freeze Sunday morning but watch for a low to bring light precip midday.
Snowpack Summary
5 to 10 cm of new snow overlies crusts in most locations except shaded terrain above 2000m. In the top meter of the snowpack, several buried suncrusts exist and may still be a concern on west, south and east aspects but in general the snowpack is well settled. Low elevation snowpacks (Field ice climbs) are isothermal and slushy.
Avalanche Summary
No new avalanches reported in the Little Yoho region over the past 24-hours. Climbing in Guinness Gully Thursday revealed a lot of old, wet debris in the gullies on Mt. Dennis and this should be expected during the afternoon periods over the next few days. Loose wet avalanches to size 2 were seen on solar aspects to treeline in Kootenay NP Friday.
Confidence
Problems
Persistent Slabs
Several buried suncrusts exist in the upper pack on S, E and W aspects although we have not had a chance to look for them for over one week. Dig down to look for these yourself, as we were surprised by a buried suncrust just last week.
Aspects: North, North East, East, South East.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Cornices
Cornices are large, and warm temperatures make them weak. Ensure you give them a wide berth on ridge crests, as they can pull back a long way when they fail and may trigger an avalanche below. If you need to travel under cornices - move quickly.
- Cornices become weak with daytime heating, so travel early on exposed slopes.
Aspects: North, North East, East, South East.
Elevations: Alpine.
Likelihood
Expected Size
Loose Wet
This problem is intended specifically for the Field ice climbs on Mts. Dennis and Stephen. We were there on Thursday, and the snowpack is slush. Hard to notice this if you just walk in the track, but be out of these gullies by noon at the latest.
- Use extra caution on solar slopes or if the snow is moist or wet.
- Make your travel plans to take advantage of overnight freezing.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Mar 26th, 2016 4:00PM
