Avalanche Forecast Little Yoho

Date Issued: Valid Until:

Parks Canada Brian Webster, Parks Canada

Avalanche Forecast

Thu May. 2nd ยท 4:32PM

Alpine

Danger Ratings Moderate

Treeline

Danger Ratings Low

Below Treeline

Danger Ratings Low
Persistent Slabs Persistent Slabs
Wind Slabs Wind Slabs
Loose Wet Loose Wet

Alpine

Danger Ratings Moderate

Treeline

Danger Ratings Low

Below Treeline

Danger Ratings Low

Alpine

Danger Ratings Moderate

Treeline

Danger Ratings Low

Below Treeline

Danger Ratings Low

Localized snow amount may very at higher elevations. Deeper areas could develop larger then expected wind slabs.

Weather Forecast

Mixed sun and cloud with isolated convective flurries forecasted through the end of the week. Forecasted strong winds on Thursday night will diminish by mid-day on Friday.

Snowpack Summary

15 to 25cm of new snow and recent winds have created soft slabs in immediate lees in the alpine. Moist snow observed up to 2400m on solar aspect, but alpine north aspects staying dry. Concern still exist for a facet layer down 30-50 cm which is producing clean shears with snow-pit tests.

Avalanche Summary

Small wet loose avalanches were observed on solar aspects on Thursday. Tuesday our field team observed two slab avalanches in the Observation Peak area. These avalanches where triggered on the persistent problem down 40 cm.

Confidence

Problems

Persistent Slabs

Persistent Slabs

This instability continues to rear its ugly head in areas where a slab sits over previously formed crusts. Though not widespread, where this layer dose exist expect it to be reactive. Tuesday we observed two large avalanches fail on this layer.

  • Dig down to find and test weak layers before committing to a line.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Likely - Possible

Expected Size

1 - 2.5
Wind Slabs

Wind Slabs

Continued precipitation and moderate winds have formed small pockets of wind slab in immediate lee features at higher elevations. Though in many areas these slab will be small, localized areas of heaver accumulation may have formed large slabs.

  • The new snow will require several days to settle and stabilize.
  • Use caution in lee areas. Wind loading could create slabs.

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

Elevations: Alpine.

Likelihood

Possible - Unlikely

Expected Size

1 - 2
Loose Wet

Loose Wet

If the sun comes out for any length of time expect loose wet avalanches out of steep sun exposed terrain.

Aspects: South East, South, South West, West.

Elevations: Alpine, Treeline.

Likelihood

Likely - Possible

Expected Size

1 - 1.5