Lizard Range and Flathead Avalanche Forecast

Issued: Apr 12th, 2021 4:00PM

Tue Apr 13th Current Conditions
Alpine Moderate Treeline Moderate Below Treeline Low
Wed Apr 14th 2 Day Outlook
Alpine Moderate Treeline Moderate Below Treeline Moderate
Thu Apr 15th 3 Day Outlook
Alpine Considerable Treeline Considerable Below Treeline Considerable

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is low. Known problems include Wind Slabs, Cornices and Loose Wet.

Watch for wind slabs lingering in steep open terrain and back off sun-exposed slopes when they heat up.

Summary

Confidence

High -

Weather Forecast

MONDAY NIGHT: Mostly cloudy skies, 40-60 km/h northeast wind, freezing level drop to valley bottom with treeline temperatures dropping to -8 C.

TUESDAY: Mostly sunny, 40 km/h northeast wind, freezing level to 1500 m with treeline temperatures around -2 C.

WEDNESDAY: Mostly sunny, 30 km/h northeast wind, freezing level to 1800 m with treeline temperatures around 0 C.

THURSDAY: Mostly sunny, 30 km/h northeast wind, freezing level to 2300 m with treeline temperatures reach +4 C.

Avalanche Summary

On Sunday a few size 1-1.5 human triggered slab avalanches were reported, including a storm slab on a north-facing convexity at treeline near Corbin. There was also a natural 30 cm thick slab on a steep east-facing slope in the Lizard Range and a size 1 skier triggered wet loose avalanche in a below treeline clearing.

Snowpack Summary

While sunny weather is melting the surface on southerly slopes, gusty northeast wind could blow around recent snow at upper elevations and form wind slabs on lee features. Upper elevations have 30-40 cm of settling snow from recent storm, but exact amounts are variable throughout the region due to the convective nature of the spring weather. The recent snow is sitting on hard crusts on solar aspects and a mix of wind affected or soft surfaces on shady aspects. The mid-pack is firm and well settled. Some faceted snow and a decomposing melt-freeze crust can be found near the base of the snowpack that may become a concern later this week when things really warm up.

The snow line is slowly creeping up the mountains to roughly 1400 m in elevation. Check out this MIN report for more details on the access from common staging areas.

Terrain and Travel

  • Be careful as you transition into wind affected terrain.
  • Pay attention to cornices and give them a wide berth when traveling on or below ridges.
  • Back off slopes as the surface becomes moist or wet with rising temperatures.

Problems

Wind Slabs

An icon showing Wind Slabs

Likelihood

Possible

Expected Size

1 - 2

As winds shift to the northeast wind slabs may be found on all aspects at upper elevations. 

Aspects:

All aspects.

Elevations:

Alpine, Treeline.

Cornices

An icon showing Cornices

Likelihood

Unlikely-Possible

Expected Size

2 - 2.5

Strong solar radiation and warming may trigger the large cornices that hang over ridgelines.

Aspects:

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

Elevations:

Alpine.

Loose Wet

An icon showing Loose Wet

Likelihood

Likely

Expected Size

1 - 1.5

Expect natural wet loose avalanches to occur on solar aspects when the sun comes out.

Aspects:

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

Elevations:

All elevations.

Valid until: Apr 13th, 2021 4:00PM

Forecast Trend

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