Forecast snowfall amounts and wind speeds are uncertain for Friday night. If the intensity of the weather is greater than expected, the avalanche danger could rise at treeline and in the alpine on Saturday.
Confidence
Fair - Forecast snowfall amounts are uncertain on Friday
Weather Forecast
Saturday: light accumulations of new snow / light southeasterly winds / freezing level @ 1000m Sunday: trace amounts of snowfall / light to moderate northwesterly winds / freezing level @ 700m Monday: light snowfall / strong westerly winds / freezing level @ 1000m
Avalanche Summary
No new avalanche activity has been reported. Expect new wind slab avalanche activity with forecast weather on Friday night.
Snowpack Summary
Light amounts of recently fallen snow (up to 20cm in the Coquihalla) sit over an assortment of old snow surfaces comprising, depending on location, crusts, old wind slab, surface hoar and surface facets. The crusts formed on all aspects below 1700m and on steep solar aspects higher up. Surface facets have grown particularly on northern aspects where colder temperatures have persisted. Lightly buried surface hoar is most prominent at treeline and below and is most likely to be found in the north and central parts of the region. The upper snowpack structure will be the thing to watch as the overlying slab develops with forecast weather. In general the mid and lower snowpack are strong and well settled. A recent profile at 1240m on a south aspect in the Coquihalla area showed a number of sudden test results in the top 100cm. Conditions reportedly improved substantially on other aspects. This is a good reminder that spatial variability exists and that we should continually make observations as we travel.
Problems
Wind Slabs
Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.