Avalanche Forecast

Issued: Mar 10th, 2017 4:06PM

The alpine rating is considerable, the treeline rating is moderate, and the below treeline rating is moderate. Known problems include Wind Slabs and Deep Persistent Slabs.

shorton, Avalanche Canada

Northwest Inland.

Danger will ramp up over the next few days with new snow, strong winds, and warming temperatures in the forecast. Stick to sheltered supported terrain.

Summary

Confidence

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

Weather Forecast

SATURDAY: Flurries starting in the morning with 3-5 cm of new snow, 20-40 km/h southeast winds, alpine temperatures around -15 C.SUNDAY: Stormy with 5-10 cm of new snow, 40-60 km/h southwest winds, alpine temperatures climbing to -5 C.MONDAY: Another 5-15 cm of snow, 60-80 km/h southwest winds, alpine temperatures around -2 C and freezing levels climb to 1200 m.

Avalanche Summary

No new avalanches were reported in the southern part of the region on Thursday. A few size 2.5 natural wind slabs were reported around Ningunsaw.Wind slab activity will likely increase over the weekend with new snow and strong winds. Warming temperatures next week will likely stress deep persistent slabs.

Snowpack Summary

Generally light daily amounts of low density snow have fallen in recent days. Strong and variable winds have likely formed wind slabs in exposed terrain. These daily accumulations have incrementally loaded a weak interface which was buried in February. This buried layer includes stiff wind slabs, facets, crusts and surface hoar. The overlying slab may have a poor bond to these interfaces, especially in areas where the slab may be stiffer and more cohesive due to winds. At treeline, the average snowpack depths are 120-190 cm and a well consolidated mid-pack of approximately up to 100 cm sits above weak basal facets (sugary snow) near the ground. The deeper basal weakness remain a concern, especially in thin rocky start zones and shallow snowpack locations.

Problems

Wind Slabs

Gusty winds from the southeast have formed fresh wind slabs. Wind slab reactivity may persist for longer than usual due to underlying persistent weaknesses.

Sheltered slopes will likely offer the best and safest riding today.Use ridges or ribs to avoid pockets of wind loaded snow.

Aspects: North, North East, East, South East, South.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Deep Persistent Slabs

A lingering weakness at the bottom of the snowpack may remain sensitive to human triggering, especially in shallow snowpack areas. Smaller avalanches in motion also have the potential to step down and trigger destructive deep persistent slabs.

Avoid steep convexities or areas with a thin or variable snowpack.Be aware of the potential for full depth avalanches due to weak layers at the base of the snowpack.

Aspects: North, North East, East, South East, South, South West, West.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Valid until: Mar 11th, 2017 2:00PM