Purcells

New snow amounts and rising temperatures are driving the hazard these days. Cornices will become weak as temperature rise. Check out the latest Forecasters Blog.

Fair - Forecast snowfall amounts are uncertain

Synopsis: A slow moving frontal system will bring precipitation into BC.Tonight: Cloudy with clear periods, precipitation should taper off. No overnight freeze and freezing levels up to 1600m. Winds moderate, gusting to strong from the south west.Saturday: Cloudy with flurries. Trace of precipitation, daytime freezing level around 1600m, winds light to moderate from the south west.Sunday: Cloudy with flurries. 5 to 10 cm of precipitation in the forecast, daytime freezing level around 1600m, no overnight freeze, winds, light to moderate from the south west.Monday:  Sunny with some cloudy periods. No precipitation in the forecast, freezing levels may climb to 2400 metres, winds light to moderate from the south west.

Reported avalanche activity has slowed down, but there are still reports of cornice failures producing large ( size 2 ) avalanches. Some stepping down to known persistent weak layers. We expect to see natural avalanche activity rise with the precipitation and winds associated with the incoming storm system today and tonight ( Friday ) along with periods of sun and increasing air temperatures later in the week.

The snowpack is highly variable across the forecast region. The last snow fall is well settled now, although there may still be wind slabs on the lee sides of ridge crests mostly north and north east. Moist snow  during the day on all solar aspects below 1800 metres, crusts later in the day when the solar aspects become shady,  Crust on north aspects in the middle elevations, and surface hoar has formed on protected north aspects.Numerous crusts can be found in the upper snowpack on south facing slopes. A March 15 crust/surface hoar interface is down approximately 50-80cm in most parts of the forecast area. At 60 to 120cm below the surface you may find surface hoar and crusts that were buried at the beginning of March. This interface is still touchy in some areas, and continues to produce sudden planar failures in compression tests.The deeper facet/crust persistent weakness buried at the beginning of February, is now down 80 to 180 cm, and still reactive in test pits. An avalanche on any of these deeper, persistent interfaces would be large and destructive. Weak basal facets exist in many areas, but  triggering is unlikely, without a big load.