Avalanche Forecast

MONDAY NIGHT: Increasing cloud overnight as freezing level drops to valley bottom, moderate wind from the southwest, treeline temperatures around - 8 C.

TUESDAY: Cloudy skies with some isolated flurries bringing trace amounts of snow, moderate to strong wind from the west, freezing level climbs to 800 m with treeline temperatures around -4 C.

WEDNESDAY: Clear skies except for a possibility of valley cloud, moderate wind from the southwest, an inversion forms with above freezing temperatures between 1500 and 2000 m.

THURSDAY: Clear skies except for a possibility of valley cloud, moderate wind from the southwest, treeline temperatures around -8 C.

Over the weekend a few notable avalanches were reported including a snowmobile triggered avalanche near Silvern Lake that appeared to occur on a 30-50 cm deep surface hoar layer, and a few size 2-3 slab avalanches triggered by heavy machinery north of Hazelton that occurred on 30-70 cm deep layers (on northeast and southeast aspects around treeline). There were also reports of some large (size 2-3) naturally-triggered avalanches on wind-loaded slopes below cornices. Large avalanches with similar characteristics were observed on Friday, including one on Hudson Bay Mountain (see photos in this MIN report) and another one north of Starr Basin in the Telkwa Range.

Wind and warm temperatures have created highly variable surface conditions. Open terrain is heavily wind-affected, surface crusts may extend into the alpine on south-facing slopes, and pockets of dry snow may still exist on northern aspects. Recent avalanche activity suggests there are two weak layers in the upper snowpack: one is a 30 cm deep surface hoar layer (buried on Jan 19) and the other is a 40 to 70 cm deep layer of faceted snow from the cold spell at the end of December. We are uncertain about the spatial distribution of these layers, but avalanche activity suggests they are most problematic in steep terrain at treeline and alpine elevations. In thin snowpack areas, the base of the snowpack is composed of weak faceted grains around various melt-freeze crusts, which are considered dormant at this time.

• Caution around convexities or sharp changes in terrain.
• Be especially cautious as you transition into wind affected terrain.
• Use ridges or ribs to avoid areas of wind loaded snow.
• Avoid shallow, rocky areas where the snowpack transitions from thick to thin.