Start and finish your trip early to manage another warm day on Thursday. A steady cooling trend with light precipitation will take us into the weekend.
Cornices are large and will weaken with sun exposure and daytime heating. Big cornice falls are a hazard on their own but can also trigger avalanches on the slopes below.
Sun and warm daytime temperatures can quickly destabilize the upper snowpack and increase the likelihood of wet loose avalanches. Pinwheeling and moist surface snow are strong signs of this kind of instability. Even small avalanches can be a hazard in high consequence terrain and above terrain traps.
Wednesday night: Clear. Light southwest winds, moderate to strong in the alpine.
Thursday: Sunny. Light southwest winds, moderate to strong in the alpine. Alpine high temperatures around +1 with freezing levels reaching 2300 metres.
Friday: Mainly cloudy with isolated wet flurries in the alpine. Moderate to strong southwest winds. Alpine high temperatures around 0 with freezing levels to 2000 metres.
Saturday: Mainly cloudy with isolated flurries. Moderate to strong southwest winds. Alpine high temperatures around -3 with freezing levels to 1700 metres.
No new avalanches were reported on Tuesday.
On Monday there were size 1 wet loose avalanches reported in the backcountry near Castle. There were wet loose avalanches size 1-2 from throughout the region out of southerly alpine terrain reported over the weekend. Similar natural or human triggered avalanche activity can be expected during the heat of the day on Thursday.
The alpine may be wind affected in open areas. Snow on all solar aspects and lower elevation bands will start out crusty but may start to get moist by mid morning. Reports suggest snow on northerly terrain above 1600 m has so far remained dry. Cornices are large and looming, and glide cracks are increasing in size...both should be considered unpredictable and given a wide berth.
Around 30 to 60 cm of snow sits above a layer of sugary faceted grains that were buried in mid-February. In some areas, there may be an old layer of feathery surface hoar or facets from late January down 50 to 80 cm deep. There have been no reported avalanches on either of these layers in the region since March 9th in the Crowsnest, but there is always lingering concern that consecutive days in a row of warm temperatures may increase the reactivity of deeper weak layers in isolated areas.
The mid pack is firm and well settled. Some faceted snow and a decomposing melt-freeze crust can be found near the base of the snowpack.
