Avalanche Forecast

Issued: Mar 28th, 2019 4:07PM

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

conrad janzen, Parks Canada

Little Yoho.

The main concern right now is daytime heating. Start and finish early to take advantage of the colder temps and reduced avalanche hazard in the mornings. Some lingering concerns for deeper weak layers also exist as we transition to spring conditions.

Summary

Weather Forecast

A mix of sun and cloud for Friday and Saturday will bring slightly warmer temperatures and increased solar inputs. Day time highs for Friday will reach +7'C at valley bottoms but stay below freezing in the alpine. Forecasted winds are generally light. We currently expect a cooler cloudy day on Sunday.

Snowpack Summary

10-20 cm of recent snow overlies a variety of surfaces depending on aspect and elevation. A supportive melt freeze crust is present below the new snow in most areas excluding high north aspects. Many areas have a cohesive mid-pack over the basal facets, while thin areas often have weak facets to ground. Lower elevations are becoming isothermal.

Avalanche Summary

Loose dry avalanches up to size 1.5 were observed above treeline on Wed/Thurs following the arrival of the new snow on Wednesday. There have been a couple isolated size 1.5 to 2 slab avalanches in the last several days running on buried facets in thin snow pack areas. This activity has slowed down with cooling but the weakness persists.

Confidence

Timing or intensity of solar radiation is uncertain on Friday

Problems

Loose Wet

Clearing skies and warming temperatures will increase the avalanche activity, especially on solar aspects in the afternoon. The recent snow will quickly loose cohesion with any direct solar inputs causing sluffing and loose wet avalanche activity.

Use extra caution on solar slopes or if the snow is moist or wet.Travel early before the heat of the day, and avoid big slopes in the afternoon.

Aspects: South East, South, South West.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 1.5

Persistent Slabs

Weak buried facets are still present in many thin areas. On higher N aspects these have not necessarily been impacted much by the recent heat. This is not currently a big concern in most areas but something to keep in mind if entering bigger terrain.

Watch for whumphing, hollow sounds and shooting cracks.

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

Elevations: Alpine.

Likelihood

Unlikely

Expected Size

1 - 2

Valid until: Mar 29th, 2019 4:00PM