Northwest Inland

A special warning has been issued for the substantial warming and sun this week. Deeply buried weaknesses within the snowpack are expected to wake-up and produce very large avalanches. It is best to avoid avalanche terrain during the heat of the day.

Moderate

The ridge of high pressure is expected to persist until Friday evening. Thursday should be sunny with light alpine wind and freezing levels reaching around 3500m in the afternoon. Increasing cloud cover is expected on Friday but mostly sunny conditions are expected for most of the day with freezing levels above 3000m. Alpine winds are expected to increase on Friday evening as the ridge breaks down. A mix of sun and cloud is currently forecast for Saturday with freezing levels dropping to around 1500m and moderate southwest winds in the alpine.

On Tuesday, widespread sluffing was reported at all elevations and well as some shallow solar triggered slabs up to size 1.5.  Cornices and glide cracks are also reported to be very active in the north of the region. No new avalanches were reported on Monday. On Sunday, a natural icefall entrained surface snow and was reported as size 2. Isolated natural wind slabs were reported to size 1 on east aspects at treeline. In the far north, natural cornice releases were reported to have triggered slabs up to size 3.5 which were stepping down to ground. Point releases were reported up to size 2 and glide cracks up to size 2.5. On Thursday, continued warming , sun exposure, and limited overnight recovery means natural cornice releases, deep persistent slab releases, and loose sluffing are expected to continue. Very large avalanches will remain a serious concern for the next few days.

Moist surface snow is being reported to ridgetop on all aspects with wet surface snow at treeline and below. Warm overnight temperatures means there was a limited refreeze of the snow surface. A thin crust may have formed in some areas but is expected to quickly break down in the morning. A weak crust/surface hoar layer which was buried over a week ago is down 20-30cm in the north of the region. A widespread crust/facet layer buried in early February and a lingering surface hoar layer from January can now be found down a meter or more. Weak basal facets also exist in some areas and have been shown to be most reactive in the north of the region. All these old weak layers still have the potential to produce large avalanches, especially with a large trigger such as a cornice fall. Extra caution is required during this period of substantial warming and intense solar radiation, as this is when these layers have the biggest potential to wake up.