Avalanche Forecast

Fair - Timing or intensity of solar radiation is uncertain

This region should remain dry on Tuesday. Freezing levels are expected to go to around 3200 m, with cloud but also good periods of sunshine. Winds light southeasterly. On Wednesday, increasing cloud cover in the afternoon will make things feel a little cooler, but freezing levels are still expected to be around 3000m. Trace amounts of precipitation could occur later in the day. On Thursday, precipitation is expected, which is expected to be heavy in the south of the region (Kaslo, 20-30 mm) and moderate in the north (Revelstoke 10-15 mm); this may fall as rain in many areas. Freezing levels falling through the day from 2000 m initially to 1500 m by the end of the day.

On Sunday, solar activity was reported up to size 2. A size 1.5 skier-triggered avalanche was reported on a north aspect at treeline with a fracture depth of around 30 cm. On Saturday a large (size 3) naturally-triggered avalanche released on a southwest aspect at 2300 m. The avalanche initiated in a shallow rocky start zone and initially pulled out the recent storm snow before stepping down to lower layers, in some places scouring all the way to ground. Another large (size 2.5) avalanche occurred on a northwest aspect at 2300 m and ran all the way to ground.

Up to 80cm of recent storm snow sits on a weak layer of facetted crystals sitting on a crust in the alpine and at treeline. This layer still reacts to snowpack testing producing sudden, "pop" results. Recent reports of remotely triggered avalanches are noteworthy and suggest the problem will not heal quickly. Wind slabs are reported to be isolated to the immediate lee of exposed features at high elevations. Spring-like, moist snow exists on all south facing slopes as well as many north facing areas. There is limited crust recovery developing at night. There is still concern for the mid-February buried surface hoar layer that is down about 140-220 cm. Avalanches releasing on this layer are a low probability-high consequence situation. Cornices in the region are very large. With warmer temperatures, and longer periods of direct solar radiation, these may become weak and fail. They could provide a large enough trigger to release these deep layers on slopes below. Cornices are large and sagging due to recent warm temperatures.