Avalanche Forecast

Issued: Apr 11th, 2018 4:00PM

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

Lisa Paulson, Parks Canada

Little Yoho.

A cooler day forecasted for tomorrow with overcast skies and flurries. If the sun does burn through, we may see isolated loose wet avalanches in solar terrain.

Summary

Weather Forecast

For Thursday, the forecast calls for mainly cloudy skies with flurries (5-10 cm) with light to moderate East wind flipping back to SW once the bulk of the snow arrives. Freezing levels will rise to only 1800 m tomorrow and return to surface overnight.

Snowpack Summary

3-5 cm of fresh snow at upper elevations with some wind effect and thin wind slabs in isolated areas. Various types of temperature crusts or moist snow found on solar aspects and found on all aspects below 1900 m. The March 15 suncrust is down 25-50 cm on solar aspects and still is a concern for skier triggering.

Avalanche Summary

Two cornice triggered avalanches size 2-2.5 in Sunshine region on a NE and S aspect, occurred late in the day yesterday. Also evidence of loose wet snow avalanches up to size 2 on solar aspects over the past few days. No natural activity noted today at the time of writing the bulletin.

Confidence

Intensity of incoming weather systems is uncertain

Problems

Wind Slabs

Wind slabs can be expected in the high alpine on lee aspects. Forecasted East wind for Thursday may reverse load some slopes.

Be careful with wind loaded pockets, especially near ridge crests and roll-overs.

Aspects: North, North East, East.

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Persistent Slabs

Forecasters are still concerned about the March 15 crust which is down 25-50 cm on steeper solar aspects. There has been sporadic but regular skier and explosive triggered avalanches on this layer over the past several weeks.

Be cautious with convexities and steep slopes on solar aspects.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2.5

Valid until: Apr 12th, 2018 4:00PM