The April Fools Day crust, up to 100 cm below the surface remains a concern, especially on east, south, or west facing slopes at treeline and higher elevations.
Expect spring conditions at elevations up to around treeline,and solar aspects well into the alpine. Warm temperatures melt the strength right out of the snowpack so avoid avalanche terrain in these areas when it's hot and sunny, late in the day, or if there isn't an overnight freeze.
A layer buried on April 1, down roughly 50 to 100 cm from the surface, appears to be most reactive on solar tilted slopes where surface hoar may sit on a hard melt-freeze crust.
A weak layer of facets exists near the base of the snowpack. The likelihood of human triggering is low given the layer's depth.
Suspect terrain includes steep, shallow, and rocky terrain where the snowpack varies between thin and thick.
On Wednesday a size 3 Glide Slab was reported on a south facing rock slab releasing near treeline. Explosive cornice control work mostly resulted in large chunks dropping but out of 10 events only 2 pulled size 2 slabs from the slopes below (in the Purcells).
A number of persistent slab avalanches were reported on Tuesday, up to size 2. They were a combination of explosive and skier triggered, and all appear to have failed on lingering and problematic April Fools Day surface hoar/crust combination. All reported avalanches occurred in the western Purcells.
In the Selkirks the avalanche activity appears to be slowing. However, many natural and human-triggered avalanches were reported last week. Many of these slid on the same April Fools Day crust, including a fatal avalanche in the western Purcells and a close call near Revelstoke.
Dry, powder snow remains at higher elevations on north-facing terrain. While multiple melt-freeze crusts or moist snow are found in the snowpack on steep solar slopes and at lower elevations.
A layer of surface hoar from March 31 persists down roughly 50 to 100 cm appears to be variable in its distribution. The surface hoar may be sitting above a crust on all but true north-facing slopes. Despite a decrease in avalanche activity on this layer, avalanche professionals continue to closely monitor it. Additionally there are similar crusts dating from April 16 and April 7 higher up in the snowpack with similar characteristics and concerns.
The mid-snowpack is strong. However, the November depth hoar remains at the base of the snowpack and remains a concern in rocky, shallow, variable depth snowpack areas at treeline and above.
Friday Overnight
Cloudy with clear periods. Flurries in places but only trace to 2 cm of precipitation. Light southwest ridgetop winds. Treeline temperatures around -4 C. Freezing level falling to valley bottom.
Saturday
Cloudy with flurries. Just a trace of snow. Light southwest ridgetop winds. Treeline temperatures around zero to -3 C. Freezing level around 2000 m.
Sunday
Warm overnight temperatures with freezing level remaining around 1500m. Cloudy with snow, accumulations from a trace up to 10 cm by end of day. Moderate southwest winds. Treeline temperatures around zero and freezing level around 2100 m.
Monday
Warm overnight temperatures with freezing level remaining around 1500m. Cloudy with another trace to 5 cm snow. Light west winds. Treeline temperatures around zero and freezing level around 2100 m.
More details can be found in the Mountain Weather Forecast.
