Avalog Join
Archived

Avalanche Forecast

Dec 31st, 2017–Jan 1st, 2018
Alpine
2: Moderate
The avalanche danger rating in the alpine will be moderate
Treeline
2: Moderate
The avalanche danger rating at treeline will be moderate
Below Treeline
1: Low
The avalanche danger rating below treeline will be low
Alpine
2: Moderate
The avalanche danger rating in the alpine will be moderate
Treeline
2: Moderate
The avalanche danger rating at treeline will be moderate
Below Treeline
1: Low
The avalanche danger rating below treeline will be low
Alpine
2: Moderate
The avalanche danger rating in the alpine will be moderate
Treeline
2: Moderate
The avalanche danger rating at treeline will be moderate
Below Treeline
1: Low
The avalanche danger rating below treeline will be low

Regions: Cariboos.

A stable weather pattern to start the new year and possible temperature inversion coming mid-week. Consider the potential to trigger persistent slabs as the recent storm snow starts to finally settle and consolidate more rapidly.

Confidence

Moderate - Freezing levels are uncertain on Wednesday

Weather Forecast

MONDAY:  Mix of sun and cloud / Light to moderate northwest wind / Alpine temperature -12TUESDAY: Mix of sun and cloud / Light to moderate west wind / Alpine temperature -5, possible temperature inversion WEDNESDAY: Cloudy with sunny breaks / Light southwest wind / Alpine temperature -1, temperature inversion

Avalanche Summary

Recent reports are of a few wind slab avalanche to size 1.5 and loose dry avalanches running in steep terrain. Some cracking and whumpfing has been reported in terrain 1500m and below over the past few days. Please submit your observations to the Mountain Information Network (MIN).

Snowpack Summary

15-30cm of low density new snow has buried a recently formed layer of weak feathery surface hoar and/or sugary facets. A layer buried mid-December that consists of surface hoar, sun crust and/or sugary facets is now down approximately 30-50cm. The bond at this old snow interface is of critical importance in areas where the overlying snow has consolidated into a slab. The most concerning areas are those that saw pronounced surface hoar development before the storm, such as sheltered areas at and below treeline, sheltered northerly aspects in the alpine, or anywhere the surface hoar formed on top of a sun crust. Recent snowpack tests show wide ranging reactivity on this weak layer. A crust which was formed by rain in late November is another major feature in the snowpack and is down approximately 70-100cm at tree line elevations. This interface has shown some signs of reactivity in the adjacent North Columbia region limited to steep, variably loaded alpine features.

Avalanche Problems

Wind Slabs

Recent shifting winds have been redistributing loose snow into wind slabs on a variety of aspects.
Use ridges or ribs to avoid pockets of wind loaded snow.Be cautious as you transition into wind affected terrain.

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

Elevations: Alpine, Treeline.

Likelihood: Unlikely - Possible

Expected Size: 1 - 2

Persistent Slabs

A weak layer of surface hoar buried 30-50 cm deep has potential to be reactive where the overlying snow has settled into a cohesive slab.
Sluffs may trigger deeper instabilities.Watch for signs of slab formation at lower elevations, such as whumphing or shooting cracks.Buried surface hoar is more likely to be preserved in sheltered openings at and below tree line.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Unlikely - Possible

Expected Size: 1 - 2