North Columbia

Wind slabs continue to surprise riders up at higher elevations. Use terrain features to your advantage while avoiding wind loaded pockets, and unsupported roll-overs.

Moderate - Timing, track, or intensity of incoming weather system is uncertain on Monday

Wind and precipitation start to kick in on Monday, before ramping up on Tuesday.MONDAY: Cloudy with flurries bringing up to 5-10 cm of new snow, increasing overnight. Moderate southwest winds 20-40 Km/hr. Freezing level 1400 metres with alpine high temperatures of -4.TUESDAY: Snow (10-15cm). Moderate to strong west winds, Freezing level to 1600 metres with alpine high temperatures around -3. WEDNESDAY: Sunny with cloudy breaks and isolated convective flurries. Moderate northwest winds 20-45 Km/hr. Freezing level to 1400 metres with alpine high temperatures around -4.

On Saturday we received reports of several wind slabs and storm slabs to size 2.5, mostly on northerly aspects above 2200m. Also on Saturday, a wet loose size 1.5 avalanche injured a skier in Glacier National Park on a west aspect near 2000m.Thursday and Friday's reports included several wind slab and storm slab releases. 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.On Wednesday a couple of smaller (size 1-1.5) ski cut and skier-triggered storm slabs failed on one of the recently buried weak layers mentioned in our snowpack discussion, down 20 cm. These occurred on northwest and west aspects in the alpine.

10-18cm of new snow fell on Thursday into Friday. Winds were moderate to strong from the south / east, transporting snow in the alpine and upper tree line, creating reactive wind slabs on immediate lee (down wind) features. 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 may be found approximately 30 and 50 cm below the surface. The deepest of these surface hoar layers was the failure plane in several slab avalanches last week.New snow amounts taper with elevation and below 1800 m, reduced accumulations have buried a supportive crust on all aspects. Deeper persistent weak layers from January and December are generally considered dormant, but could wake up with a surface avalanche stepping down, 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.