Avalanche Forecast

Issued: Apr 14th, 2018 4:39PM

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

jsmith, Avalanche Canada

Lizard-Flathead.

Rising temperatures and the chance for a bit of sunshine on Sunday may be enough to trigger loose wet avalanches on steep slopes facing the sun.

Summary

Confidence

Moderate - Timing, track, or intensity of incoming weather system is uncertain

Weather Forecast

SUNDAY: Mostly cloudy with sunny breaks. Moderate southwesterly ridgetop winds. Alpine temperature +5. Freezing level rising to around 2000 m.MONDAY: Snow, accumulation 10-20 cm. Moderate to strong southeasterly ridgetop winds. Alpine temperature +2. Freezing level around 1500 m.MONDAY NIGHT: Snow, accumulation 10-15 cm. Moderate southwesterly ridgetop winds. Freezing level around 1000 m.TUESDAY: Snow, accumulation 5-10 cm. Moderate westerly ridgetop winds. Alpine temperature +1. Freezing level around 1500 m.

Avalanche Summary

Several naturally triggered wind slabs up to size 2 were reported near Fernie on Friday.

Snowpack Summary

10-20 cm of recent storm snow and moderate winds have formed wind slabs sitting on hard crusts on lee features at treeline and above which may be reactive to human triggers. The upper snowpack contains numerous crusts.The mid-pack is generally well settled and strong.A layer of sugary facets around a crust can be found near the bottom of the snowpack which has been inactive for some time. This layer may be triggered by large triggers, such as a falling cornice, or by a major warm-up to the snowpack.

Problems

Loose Wet

When the sun comes out it will quickly weaken the new snow and cause loose wet avalanching on steep solar slopes.

Cornices become weak with daytime heating. Give them a wide berth both from above and below.Minimize exposure to sun exposed slopes when the solar radiation is strong.Watch for signs that the snow is heating up such as pin-wheeling or the surface snow becoming moist.

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

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2

Wind Slabs

Recent storm snow and strong winds have formed wind slabs in leeward areas near ridge crests and on convex features which may be reactive to human triggers.

Avoid shallow, rocky areas where the snowpack transition from thin to thick.Avoid areas that look freshly loaded with snow; especially convex features below ridgetops.Use caution when transitioning into wind effected terrain.

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

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Apr 15th, 2018 2:00PM