Avalanche Forecast

Issued: Jan 14th, 2019 3:44PM

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

jfloyer, Avalanche Canada

Lizard-Flathead.

Some avalanche danger remains in alpine areas, in wind loaded pockets and on steep, thin/rocky slopes.

Summary

Confidence

High -

Weather Forecast

MONDAY NIGHT: Clear skies. Temperatures dropping to around -14C.TUESDAY: Dry and sunny above some valley cloud. Expect cool treeline and alpine temperatures, around -4C. Calm winds.WEDNESDAY: Dry with a mix of sun and cloud. Treeline temperatures around -6C. Light southwesterly winds.THURSDAY: Light snowfall, 2-4 cm. Treeline temperatures around -9C. Light easterly winds.

Avalanche Summary

On Saturday control work produced wind slab avalanches to size 2 on northeast facing features. A size 2 natural deep persistent slab was also reported on a south facing aspect around 2100 m. We're very grateful that a group of sledders shared a fantastic MIN report about their near miss here. A large avalanche was triggered on a thin, rocky, southwest facing feature near ridgecrest, the photos tell a compelling story about the structurally weak snowpack that exists in many places in the region. On Friday natural avalanches size 1.5 to 2 were reported from northeast through northwest facing terrain at and above treeline. Control work produced storm slab avalanches to size 2.5 on similar aspects. Control work also caused cornices to fail on southeast facing terrain which subsequently produced storm slab avalanches to size 1.5.

Snowpack Summary

Recent sunshine and warm alpine temperatures have created moist/crusty surfaces on solar aspects. The snow appears to have remained dry on shady aspects. Wind slabs have become difficult to trigger.In shallow snowpack areas, the base of the snowpack may still be composed of weak faceted grains. In deeper snowpack areas, the middle and lower portions of the snowpack are generally considered to be well-settled and strong.

Problems

Wind Slabs

Up to 30 cm of recent snow has formed a storm slab which may be a bit more reactive as warm temperatures apex on Monday, especially in wind loaded areas near ridgecrest.

Extra caution needed around cornices with current conditions.Be cautious as you transition into wind affected terrain.Be careful with wind loaded pockets, especially near ridge crests and roll-overs.

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 2

Deep Persistent Slabs

The possibility of large releases remains in shallow snowpack areas. The chance of triggering is highest on steep rocky alpine slopes that have thin and/or variable snow cover.

Avoid steep slopes in shallow snowpack areas where triggering is more likely.Give rocky outcrops a wide berth in steep terrain.

Aspects: All aspects.

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Valid until: Jan 15th, 2019 2:00PM