Watch for fresh wind slab development as new snow accumulations build. Expect reactivity, slabs form over a surface hoar and crust combination.
Small but reactive new wind slabs are likely form with snowfall overnight Saturday and into Sunday. Expect to find wind loading on all aspects as winds switch from north to southwest. Slabs may be poorly bonded to the crust below.
Warm temperatures and sunshine on Friday caused wet loose avalanches at low elevations to size 1.5.
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In exposed terrain at higher elevations, pockets of wind slab sit in wind loaded features while rocks may be exposed on others. Large surface hoar has been reported on the surface in sheltered areas, with a crust present on solar aspects. 40 to 70 cm of settling snow sits in the upper snowpack.
The mid and lower snowpack consist of crusts and facet layers which are ongoing concerns in this area. Reports suggest that these layers are stronger than what's found in other regions (e.g. the Duffy or Hurley). Recent test results show these layers are reactive, however there has been no significant avalanche activity reported yet.
Snowpack depths at treeline reach 200 cm in some areas, but decrease rapidly below 1500 m.
An Arctic front dominates the weather over BC. Light snowfall is expected Saturday night as a low south of Vancouver Island briefly competes with the cold air, directing snowfall up the Fraser Valley.
Saturday Night
Mostly cloudy with moderate to strong westerly winds. Freezing level below valley bottom. Snowfall expected, up to 10-15 cm in the Fraser Valley.
Sunday
Partly cloudy with around 5-15 cm of snow expected, again favoring the Fraser Valley. Moderate to strong westerly winds at ridgeline. Freezing level below valley bottom. Alpine high of -15 °C.
Monday
Mostly cloudy with moderate to strong southwest winds. Alpine highs of -20 °C. Isolated flurries possible.
Tuesday
A mix of sun and cloud with moderate westerly winds. Freezing level below valley bottom. Moderate snowfall possible with alpine high temperatures of -25 °C.
More details can be found in the Mountain Weather Forecast.
