Avalanche Forecast

Archived

Apr 25th, 2019–Apr 26th, 2019

Alpine

Below Threshold.

Treeline

Below Threshold.

Below Treeline

Below Threshold.

Alpine

Below Threshold.

Treeline

Below Threshold.

Below Treeline

Below Threshold.

Alpine

Below Threshold.

Treeline

Below Threshold.

Below Treeline

Below Threshold.

Regions

Little Yoho.

Winter returns - expect the hazard to increase through the weekend with the incoming snow and wind. LP

Weather Forecast

Cloud moves in Thurs. evening with snow beginning Friday afternoon. Winds pick up Sat with increased snow, especially in the Eastern part of the region. Expect some reverse loading onto sun crusts with the strong NE winds. Amounts range from 20-30 cm by Sunday evening.

Snowpack Summary

Last week's storm snow settling and bonding, but the early April facet layer is still evident as a weak interface. Some small wind slabs in alpine lees and natural cornice failures with daytime heating . Melt freeze crusts present on solar aspects and at treeline and below breaking down with solar inputs. .

Avalanche Summary

One avalanche involvement today in a couloir on Narrao Shoulder. On a NE aspect at 2900 m, a cornice failure triggered a size 1.5 wind slab, which was initially 20 cm deep and then steeped down to approximately 40 cm deep. No other avalanches reported, but suspect other similar avalanches are occurring together with loose wet with daytime heating.

Confidence

Problems

Wind Slabs

Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.