With uncertainty about diminishing storm instabilities and persistent layers still in play, we're approaching maximum snowpack complexity. It's a good time to travel conservatively.
A heavy load of new snow is settling above multiple weak layers present roughly 1 - 2 m deep. Recent avalanches failing on these layers have been large and destructive, and the problem hasn't disappeared.
New snow accumulations are settling over mid-storm interfaces and a crust now buried up to 1 m deep. Wind loaded areas will likely be the most triggerable but all steep slopes should be treated with caution while the new snow stabilizes.
Wednesday's reports were a busy mix of storm-induced activity. Notables included ski cut size 1.5 persistent slab on 70 cm-deep surface hoar, a size 1.5 storm slab triggered by a skier in the Esplanades, and explosives-triggered storm/wind and persistent slabs to size 3.5 in the TC Highway corridor.
Persistent slabs eased off a bit, but the problem lingers. This MIN report of large remotely-triggered persistent slabs in the Esplanades captures recent activity well.
Storm snow since March 7 totals 70 - 100 cm around Revelstoke and 30 to 50 cm farther south. It sits on hard old wind effect in exposed terrain treeline and above and on a crust extending to 1800 m in the north and 2200 m in the south. The thicker the crust, the more effectively it caps problems below it.
These problems include three layers in the mid-snowpack, still suspect after a widespread avalanche cycle involved them on the weekend.
One or two surface hoar layers buried in February are found 60 to 120 cm deep. In some areas these sit on a thin crust.
A deeper, widespread layer buried in late January, made up of surface hoar, facets, and/or a crust, sits 100 to 180 cm deep.
The snowpack below this is generally strong.
Thursday Night
Mostly cloudy with flurries bringing about 5 cm of new snow, closer to 10 cm north of Revelstoke. 20 to 40 km/h southwest ridgetop wind, easing. Treeline temperature -11 °C.
Friday
Mostly cloudy with scattered flurries bringing up to 5 cm of new snow. 30 km/h west ridgetop wind. Treeline temperature -10 °C.
Saturday
A mix of sun and cloud with isolated flurries bringing less than 5 cm of new snow, including overnight. 20 km/h northwest ridgetop wind. Treeline temperature -11 °C.
Sunday
Mostly sunny. 20 to 30 km/h northwest ridgetop wind shifting southwest, increasing. Treeline temperature -13 °C.
More details can be found in the Mountain Weather Forecast.
