Avalanche Forecast

Issued: Mar 5th, 2019 5:07PM

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

shorton, Avalanche Canada

Lizard-Flathead.

Be cautious on steep features at lower elevations. where a persistent slab problem lingers. A weak storm will bring more low density snow on Wednesday night.

Summary

Confidence

Moderate - Forecast snowfall amounts are uncertain

Weather Forecast

TUESDAY NIGHT: Clear with cloudy periods, light northeast wind, alpine temperatures drop to -15 C.WEDNESDAY: Cloudy with isolated flurries, trace accumulations, 20-40 km/h southeast wind, alpine high temperatures near -10 C.THURSDAY: Scattered flurries easing throughout the day with 5-15 cm of snow, 40-60 km/h southwest wind, alpine high temperatures near -5 C.FRIDAY: Cloudy with sunny breaks and isolated flurries, 30-50 km/h southwest wind, alpine high temperatures near -7 C.

Avalanche Summary

A few small loose dry avalanches were reported on Tuesday. On Monday, one small (size 1) skier triggered slab avalanche was reported on an east aspect at 1850 m.

Snowpack Summary

A mix of hard and soft wind slabs can be found in open alpine terrain, while pockets of soft snow can be found in sheltered and shaded areas. Sun crusts can also be found on south-facing slopes. There are potentially three layers of surface hoar in the upper snowpack. One is down 30-50 cm, another is down 40-80 cm, and the last one is down 80-120 cm. These layers have been most prominent and reactive between 1600 and 1900 m over the past month. The lower portion of the snowpack is generally strong.

Problems

Persistent Slabs

Buried surface hoar layers have been a problem at lower elevations over the past month. Although the likelihood of triggering these layers has decreased, this problem still warrants conservative travel in steep open terrain.

Be aware of the potential for wide propagation.Use caution on open convex rolls at and below treeline where buried surface hoar may be preserved.Watch for whumpfing, hollow sounds, and shooting cracks.

Aspects: All aspects.

Elevations: Treeline, Below Treeline.

Likelihood

Unlikely - Possible

Expected Size

1.5 - 2

Wind Slabs

Wind slabs could be reactive to human triggering at upper elevations.

Avoid freshly wind loaded features.Use ridges or ribs to avoid pockets of wind loaded snow.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 1.5

Valid until: Mar 6th, 2019 2:00PM