Over the weekend, a break in the storm should improve avalanche conditions, although wind affected slopes need to be treated with caution. Another storm is expected Monday. Watch snow amounts with this storm and increase danger to HIGH if more than 25 cm new snow arrives.
Fresh snow combined with moderate to strong winds continue to fuel wind slab formation. Likelihood shown in the graphic applies over the weekend for wind-affected slopes. On Monday, new snow and strong winds will increase the likelihood of avalanches.
Friday night: mostly dry. Light westerly winds. Treeline temperatures around -10.
Saturday: Flurries. Winds increasing to strong southwesterly in the afternoon. Treeline temperatures rising to around -6C in the afternoon.
Sunday: Flurries or light snow. Moderate westerly winds. Treeline temperatures around -6C.
Monday: Around 15 cm new snow expected. Strong southerly winds. Temperatures riding to around -2C.
The most recent observations were on Wednesday, when one size 2.5 and several size 1 storm/wind slab avalanches occurred on lee slopes including on slopes at relatively low elevations (1200 m or so). From approximately Feb 1-4 there was an extensive avalanche cycle with many avalanches noted up to size 3, mainly on north aspects.
Over the weekend, I would only anticipate natural avalanches on steep slopes in very windy areas, although human-triggered avalanches remain possible on wind-affected slopes. Avalanche danger will rise in response to forecast new snow and wind on Monday.
Recent new snow has been redistributed by winds blowing from the south to west quadrant. Wind effect is widespread in exposed areas. Recent snowpack tests indicate sudden "pop" results at the base of recent storm snow down around 50 cm. There is reported to be excellent powder and riding in more wind protected / sheltered areas.
Snow depths at White Pass are around 150 cm at our wind protected Fraser study plot. Deeper locations (higher terrain west of the highway) have more than 200 cm, while on the east of the highway depths are around 175 cm. It's reasonable to expect a thin snowpack composed mainly of sugary facets in the Wheaton Valley, and thinner wind-scoured alpine areas.
