Avalanche Forecast

Issued: Nov 29th, 2015 8:15AM

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

Avalanche Canada jlammers, Avalanche Canada

Continued warming on Monday may increase the Avalanche Danger, especially at higher elevations.If you are out in the mountains, please share your observations on the MIN

Summary

Weather Forecast

Expect clear skies and valley cloud on Monday as the dry ridge of high pressure holds on for one more day. A strong inversion is forecast to deliver alpine temperatures of about 5' celsius. Below 1800m, temperatures should remain well below freezing. Monday's ridgetop winds should remain light from the northeast. The ridge should start to break down on Tuesday with increased cloud developing throughout the day. By Wednesday we may see trace amounts of new snow. Ridgetop winds are expected to be moderate from the southwest on Tuesday, and then strong and southwesterly on Wednesday. Freezing levels should hover around valley bottom for both days.

Avalanche Summary

No recent avalanches have been reported. Given our current inversion, I would expect some loose wet avalanche activity on steep, sun-exposed slopes. If you are out in the mountains, please post your observations to the Mountain Information Network.

Snowpack Summary

Snowpack observations have been very limited as the season commences. Initial reports suggest there is enough snow above around 1700m for avalanches to occur. Terrain below treeline is reported to be below threshold for avalanche activity.Current surfaces are likely a mix of stubborn wind slabs in exposed higher elevation terrain, and loose faceted snow and surface hoar in more sheltered areas. Depending on the time of day, steep south-facing slopes at higher elevations may be moist or re-frozen. About 15cm below the surface you may find a thick rain crust which exists up to at least treeline elevation. Where it exists, this crust has added strength to the current snowpack. That said, the combination of a crust, facets and surface hoar could prove to be a significant weak layer when it finally snows again. In general there is a lot of uncertainty regarding snowpack structure throughout the region. I would dig down and test for weak layers before committing to any steeper lines.

Problems

Loose Wet

An icon showing Loose Wet
Unseasonably warm temperatures and sun will increase the chances of loose wet avalanche activity on steep, sun-exposed slopes in the alpine and at treeline. Watch for conditions that change with aspect, elevation and time of day.
Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.>Watch for clues, like sluffing off of cliffs, that the snowpack is warming up. >

Aspects: North.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Wind Slabs

An icon showing Wind Slabs
Continued warm temperatures should help decrease the reactivity of recently formed wind slabs. Watch for triggering in steep, unsupported terrain, especially in spots where a hard underlying crust exists.
Be cautious as you transition into wind affected terrain. >If you are increasing your exposure to avalanche terrain, do it gradually as you gather information. >

Aspects: North, North East, East.

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Valid until: Nov 30th, 2015 2:00PM