Avalanche Forecast

Fair - Forecast snowfall amounts are uncertain on Wednesday

Snow is expected to continue during the day on Tuesday and taper off during the night, bringing an additional 5-10 cm for the interior regions by Wednesday morning. A weak upper ridge is forecast to build over the southern interior on Wednesday that should cause light southwesterly winds and scattered flurries. There may be periods of sun in the eastern Monashees and Selkirks, and in the northern Purcells. A weak upper trough is forecast to push up from the U.S. border on Thursday bringing moderate precipitation to the southern and Eastern regions. Freezing levels are expected to climb up to about 1800 metres as the trough advances. The upper flow is expected to shift to the southeast with light alpine winds, broken skies with sunny periods, and freezing levels up to 1800 metres in the south and east regions of the interior.

We are still getting reports of large avalanches that are a couple of days old that failed on the mid-February persistent weak layer. There were a couple of new reports of small avalanches that failed in the top 50-70 cm of recent storm snow. There were two size 3.0 avalanches that were triggered accidentally by snowmobilers in the far south of, or just outside the region near Kimberley. The PWL is becoming a low probability, high consequence avalanche problem.

Strong southerly winds combined with 10-15 cm of new snow created new windslabs in the alpine and at treeline. Sunny periods on Sunday developed a sun-crust on southerly aspects up well into the alpine. The recent storm snow is reported to be bonding well to the old surface. There is a persistent weak layer (PWL) of buried surface hoar from mid-february that is buried between 100-200 cm that is the main concern. This PWL shears with a fracture character that promotes wide propagations that result in very large avalanches. Reports of avalanches on this layer are becoming less frequent.