Avalanche Forecast

Issued: Feb 4th, 2019 4:42PM

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

kdevine, Avalanche Canada

Cariboos.

Natural avalanche activity has slowed down, but human triggered avalanches remain likely, especially in wind loaded areas and at lower elevations where a buried surface hoar layer has produced avalanches recently.

Summary

Confidence

Moderate -

Weather Forecast

MONDAY NIGHT - Clear with cloudy periods / northeast winds 10-20 km/h / alpine low temperature near -19TUESDAY - A mix of sun and cloud / northwest winds 10-15 km/h / alpine high temperature near -15WEDNESDAY - Mainly sunny / west winds 15-25 km/h / alpine high temperature near -13THURSDAY - Cloudy with flurries, 5 cm / southwest winds, 15-35 km/h / alpine high temperature near -12

Avalanche Summary

Observations were limited due to high winds and poor visibility, but no new avalanches were reported on Sunday. Recent test results suggest that the new snow is not bonding well to a persistent weak layer that was buried in mid January.Widespread avalanche activity was reported on Saturday. Natural avalanches to size 3 and human triggered avalanches to size 2 were reported. Many of these failed on mid January persistent weak layer. This layer was the most reactive at treeline and below.There is a great MIN report here detailing the reactivity of the mid January layer in Allen creek on Saturday.Field observations were limited on Friday, but it is likely that a natural avalanche cycle was occurring throughout the day. There were reports of a few human triggered avalanches to size 2 occurring at treeline and below on Friday. Some of these were remote triggered (triggered from a distance), and failed on the in mid January layer.There are two great MIN reports that outline how reactive the mid January layer was on Friday. They can be found here and here.

Snowpack Summary

30-60 cm of recent new snow is sitting on surface hoar (feathery crystals), facets (sugary snow) and a crust on sun-exposed slopes. In many areas, recent strong winds have redistributed the new snow and formed wind slabs on all aspects due to shifting wind directions.50-80 cm of snow now sits on a persistent weak layer that was buried in mid January. This layer consists of surface hoar and a crust on sun-exposed slopes. It is most prominent at treeline and below, and was very reactive during the recent storm.

Problems

Persistent Slabs

50-80 cm of snow sits above a weak layer of surface hoar and crust that was buried in mid January. This layer may still be reactive to human triggers.

Any steep opening in the trees should be treated as suspect right now.

Aspects: All aspects.

Elevations: Treeline, Below Treeline.

Likelihood

Possible - Likely

Expected Size

1.5 - 3

Wind Slabs

30-60 cm of recent snow has been redistributed by recent winds in many areas, forming wind slabs on all aspects due to a shift in wind direction.

Be careful with wind loaded pockets, especially near ridge crests and roll-overs.If triggered, wind slabs may step down to deeper layers and result in even larger avalanches.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Valid until: Feb 5th, 2019 2:00PM