Avalanche Forecast

Moderate - Timing or intensity of solar radiation is uncertain on Sunday

Cloudy with some wind on Sunday before steady snow fall on Monday-Tuesday. SUNDAY: Mainly cloudy with isolated flurries and a trace of new snow, increasing overnight. Moderate southwest winds 20-40 Km/hr. Freezing level to 1200 metres with alpine high temperatures around -5.MONDAY: Cloudy with continuing flurries bringing 5-15 cm of new snow, increasing overnight. Moderate to strong southwest winds. Freezing level to 1300 metres with alpine high temperatures of -7.TUESDAY: Snow (10-15cm). Moderate to strong west winds, Freezing level 1500 metres with alpine high temperatures around -1.

On Friday, size 1 storm slabs were reported, running naturally and also when cut by skiers.Thursday's reports included several wind slab and storm slab releases in the North Columbias. These were natural as well as skier triggered and ski cut, mainly from size 1 to 1.5, and occurred on a range of aspects at treeline and above.Reports from early in the week included several small (size 1) skier-triggered and ski cut storm slabs on high elevation north aspects. These slabs failed on a surface hoar layer buried earlier this month that is mentioned in our snowpack discussion, found down about 25 cm at the time. Looking forward, newly formed wind slabs are likely to remain reactive to human triggering over the near term. Watch for intervals of solar exposure to destabilize slabs as well as promote loose wet avalanche conditions on steeper, sun-exposed slopes.

Convective snowfall coupled with strong southerly winds brought a wind-affected 5-15 cm of new snow to the region since Thursday night. The new snow has buried a couple of recent layers of storm snow that are separated by temperature and sun crusts at lower elevations and on south aspects. Surface hoar layers have been reported between these storm snow layers on shaded aspects at higher elevations and can likely now be found at approximately 20 and 40 cm below the surface. The deepest of these surface hoar layers was the failure plane in several slab avalanches earlier this week.New snow amounts taper with elevation and below about 1800 m, reduced accumulations have buried a supportive crust on all aspects.Persistent weak layers from early January and mid-December are still being reported by local operators. They are generally considered dormant, but could wake up with a surface avalanche stepping down, a large cornice fall, or a human trigger in a shallow or variable-depth snowpack area. These layers consist of sun crust, surface hoar and/or facets.