Avalanche Forecast

Issued: Mar 19th, 2018 4:14PM

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

mgrist, Avalanche Canada

Lizard-Flathead.

Pay close attention to how the new snow is bonding to the old snow surfaces. Avalanche danger will increase rapidly on sunny slopes, if the sun makes an appearance on Tuesday.

Summary

Confidence

Low - Timing or intensity of solar radiation is uncertain on Tuesday

Weather Forecast

We're in between storm systems for the next two days. More snow (10cm+) on Thursday. TUESDAY: Cloudy with sunny breaks and scattered flurries. Light to moderate westerly winds. Alpine temperature +2 C. Freezing level 1700 m.WEDNESDAY: Cloudy with sunny breaks and scattered flurries. Light to moderate westerly winds. Alpine temperature +3 C. Freezing level 1900 m.THURSDAY: Snow (10 cm). Moderate southerly winds. Alpine temperature +3 C. Freezing level 2000 m.

Avalanche Summary

On Monday we received reports of several natural size 1.5 dry loose avalanches, and confined to the recent storm snow. On Friday and Saturday, several small wet loose avalanches to size 1.5 were reported on sunny aspects at all elevations. A size 1.5 natural cornice failure was also reported on a high north east facing ridge line, which did not trigger any slabs below.

Snowpack Summary

10-12cm of new snow fell Sunday overnight into Monday. This new snow sits on a wide variety of old surfaces: a melt-freeze crust on sunny aspects, or surface hoar (up to 30mm in size) and/or dry snow on north aspects above 1500-1800m.Deeper in the snowpack, the mid-December and late-November weak layers are composed of crusts and sugary facets, which are down 150-300 cm. These layers have been dormant but may be awoken by a large trigger, such as a cornice fall, or by humans traveling in thin-to-thick snowpack areas.

Problems

Storm Slabs

The new snow from Sunday-Monday may not bond well to underlying surfaces. Dry loose sluffs may run fast and far, especially if the new snow sits on a slippery melt-freeze crust.

Keep an eye out for localized areas of deeper snow accumulation, and pockets of wind slab.Use caution in lee areas in the alpine and tree line. Storm snow may form touchy slabs.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 2

Loose Wet

If the sun comes out on Tuesday, expect the new snow to become reactive and/or slide naturally.

Avoid exposure to sunny slopes.Be cautious of sluffing in steep terrain, particularly where the debris flows into terrain traps.Watch for signs that the snow is moistening such as pin-wheeling and point-releases below cliffs

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

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 2

Valid until: Mar 20th, 2018 2:00PM