Purcells

Special Public Avalanche Warning in effect for this region for the Easter Long Weekend.

Moderate - Timing or intensity of solar radiation is uncertain

Moderate northwest winds with flurries or light snow overnight. Freezing level dropping down to 800 metres by Friday morning. Skies becoming broken or scattered cloud during the day with light westerly winds and freezing levels climbing to at least 1500 metres. Mostly sunny on Saturday with an overnight freeze down close to valley bottoms. Light westerly winds during the day with freezing levels climbing up to 1700 metres. Cloud developing by Sunday morning with light southwest winds and some chance of flurries in the late afternoon.

No new avalanches reported. Some explosives control on cornice on Tuesday resulted in releases up to size 2.5 on northerly aspects. We had a report on Monday of another skier remote triggered avalanche size 2.5 from 200 metres away on a southeast aspect at 2320 metres, believed to have released on the February 27th weak layer. A MIN report from Monday at Gorman lake in the Dogtooth range describes "a lot of cornice failures", as well as "many slides running full path." On Sunday, large cornice releases triggered persistent slabs on slopes below up to size 3.0 in the central part of the region, and a group of skiers remotely triggered a size 2.5 from 6 metres away on a southeast aspect at 2400 metres in the north of the region.

Forecast new snow and wind are expected to develop a new storm slab above a mix of crusts on solar aspects, moist snow up to about 1800 metres, and dry snow or recent wind slabs on shaded high alpine aspects. Cornices continue to be described as large and fragile, and may fail with additional loading from forecast snow, or from high daytime temperatures. Buried persistent weak layers continue to be a concern for remote triggering in isolated areas where crusts are not strong enough to "bridge" the weakness. The late February surface hoar/crust weak layer is down 40-90 cm. This layer is still reactive to human triggers in some places while in other spots it's really tough to trigger, and there's not much of a reliable pattern telling us what exact aspects are most suspect. Deeper weak layers from mid-February and early January are now down 50-90cm and 70-120cm respectively. Triggering an avalanche on either of these layers has become unlikely but still has the potential to produce very large avalanches in isolated locations.