Avalanche Canada swerner, Avalanche Canada

South Rockies Avalanche Forecast

Nov 30th, 2018 4:18PM

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

Its time to do a snow dance, South Rockies! Observations are are very limited, so make sure to supplement this forecast with your own observations. If you've been out please post your observations to the Mountain Information Network.

Summary

Confidence

Low - Due to the number of field observations

Weather Forecast

Mostly cloudy skies, cooling temperatures and dry conditions moving forward into the weekend. SATURDAY: Mostly cloudy with a trace of new snow/ alpine temperatures near -7/ generally light winds from the northeast/ freezing level 1300 mSUNDAY: Cloudy with a trace of new snow/ alpine temperatures near -12/ ridgetop winds light from the northeast/ freezing levels 1000 mMONDAY: Cloudy with sunny periods/ alpine temperatures -11/ ridgetop winds light from the northeast/ freezing levels valley bottom

Avalanche Summary

No new avalanches have been reported in the region. However, we currently have very limited observations which allows for much uncertainty in the snowpack. Check out the FORECASTER BLOG post to read deeper into those uncertainties. If you have been out, please submit any observations to the Mountain Information Network MIN.

Snowpack Summary

Recent new snow up to 20 cm and southwest winds have formed pockets of wind slab on leeward terrain, however the winds have switched from a more northeasterly direction which are potentially redistributing the new snow. Below the surface exists a series of crusts and a spotty, feathery surface hoar layer. We have a lot of uncertainty around this weak layer and its hard to know where it actually exists and how reactive it is. If you were to find it, I suspect it could exist on sheltered slopes in the alpine and at treeline. A mixed layer melt-freeze crusts and sugary facets buried late October can be found at the base of the snowpack at treeline and in the alpine. This layer has not been active, but there is potential for slab avalanches on this layer given the current snowpack structure. I suspect its likely found in terrain features like smooth alpine bowls with variable snowpack depths. Average snowpack depths at treeline are near 70 cm and taper quickly as elevation decreases. Snow depths below tree line are generally below the threshold depth to produce avalanche.

Problems

Wind Slabs

An icon showing Wind Slabs

Likelihood

Possible

Expected Size

1 - 1.5
Recent wind has likely formed isolated pockets of wind slab in the lee of exposed features at upper elevations.
Be careful with wind loaded pockets, especially near ridge crests and roll-overs.Increase your caution as you transition into wind affected terrain.

Aspects:

North, North East, East, North West.

Elevations:

Alpine, Treeline.

Valid until: Dec 1st, 2018 2:00PM