Little Yoho Avalanche Forecast

Issued: Apr 9th, 2021 4:00PM

Fri Apr 9th Current Conditions
Alpine Considerable Treeline Moderate Below Treeline Low
Sat Apr 10th 2 Day Outlook
Alpine Moderate Treeline Moderate Below Treeline Low
Sun Apr 11th 3 Day Outlook
Alpine Moderate Treeline Moderate Below Treeline Low

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

More wind slab development at upper elevations will keep the avalanche hazard elevated Saturday.

Uncertainty exists around the persistent layers in the snowpack, as some deep releases have occurred recently and lowered our confidence.

Summary

Weather Forecast

5 to 10cm of snow starting Friday night into Saturday, this new snow will be redistributed by moderate to strong wind in the alpine. These winds are expected to tapper throughout the day. Temps will stay cool this weekend with freezing levels remaining at valley bottom.

Snowpack Summary

Up to 30cm of new snow now buries a crust up to 1800m, higher on steep solar aspects. New wind slab growth in the alpine down into tree line. Several persistent layers exist in the mid to lower snowpack and have been responsible for several large avalanches. These layers will remain a concern for some time due to their uncertainty.

Avalanche Summary

A loose dry avalanche cycle occurred with increased winds Friday. Over the past week we have observed and received reports of several cornice failures and small slab releases digging down and triggering deep releases up to size 3.5.

Confidence

Problems

Wind Slabs

An icon showing Wind Slabs

Likelihood

Likely - Possible

Expected Size

1 - 2

30cm of new snow since Thursday with moderate to strong winds have formed new wind slab in alpine and open tree line terrain. Though we have limited observations of avalanche activity, we expect this problem to be reactive over the next few days.

  • Be careful with wind loaded pockets, especially in steep confined alpine terrain.

Aspects:

North, North East, East, South East, North West.

Elevations:

Alpine, Treeline.

Persistent Slabs

An icon showing Persistent Slabs

Likelihood

Possible - Unlikely

Expected Size

2 - 3.5

Several deeper releases occurred over the past week (see avalanche table). There is a lot of uncertainty as to which layers within the snowpack these slid on. We will be monitoring this in the coming days to see if it continues.

  • Pay attention to overhead hazards like cornices which could trigger persistent slabs.
  • Pockets of persistent slabs linger on alpine lee features.

Aspects:

All aspects.

Elevations:

Alpine.

Loose Dry

An icon showing Loose Dry

Likelihood

Likely

Expected Size

1 - 1.5

Anticipate loose dry activity in steep alpine terrain, especially in confined or exposed terrain features where even a small sluff can have severe consequences.

  • Be careful of loose dry power sluffing in steep, confined or exposed terrain.
  • If triggered dry loose point releases can form deeper deposits in terrain traps.

Aspects:

All aspects.

Elevations:

Alpine.

Valid until: Apr 10th, 2021 4:00PM

Forecast Trend

The latest forecast danger ratings, broken down to elevation. See how an elevation is trending.