Avalanche Forecast

Issued: Jan 30th, 2014 8:12PM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is moderate. Known problems include Deep Persistent Slabs, Loose Dry and Wind Slabs.

Tim Haggarty, Parks Canada

Waterton Lakes.

Watch for forecast winds to create slabs. Remember to consider the deep persistent problem in all of your terrain choices.

Summary

Weather Forecast

Cold and dry period with a chance of flurries Fri and Sun. The wind will be the big variable with strong NW winds possible early Friday and strong N winds early Saturday. Often winds from this direction have minimal impact on the terrain near the divide however expect rapid slab formation if they do as there is a great deal of snow for transport.

Snowpack Summary

Jan 22 hard surfaces in many areas were buried by 10cm . This snow rotted (facetted) for a few days or melted into the strong crusts on S aspects. Jan 27 strong winds created thin slabs in open areas TL and above. Wed brought 10 to 15cm of new snow. November snow 30 cm above the ground remains weak. Snowpack distribution is highly variable.

Avalanche Summary

A few loose dry natural events have occurred in steep and cliffy terrain. Skiers in steep terrain Monday found the recent snow sluffed easily and ran well on the hard Jan 22 surfaces beneath. Buried windslabs also reacted to skiers in a few places failing on the weak facetted snow that fell Jan 22.

Confidence

Wind speed and direction is uncertain on Friday

Problems

Deep Persistent Slabs

30 cm above the ground, this weak snow is a serious concern. Travelers should carefully consider snowpack depth, terrain shape, and slope angle. Use your probe to confirm depths when you are uncertain.

Carefully evaluate and use caution around thin snowpack areas.Dig down to find and test weak layers before committing to a line.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely

Expected Size

2 - 3

Loose Dry

The recent snow fails easily in steep terrain up to 25cm deep. Expect this to dissipate as the wind moves in.

Good group management is essential to manage current conditions safely.On steep slopes, pull over periodically or cut into a new line to manage sluffing.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

1 - 1

Wind Slabs

Northerly winds are expected. New wind slabs could form very quickly as there is a lot of snow available. Expect to find different distribution to these slabs compared with the prevailing Westerly winds.

Be careful with wind loaded pockets, especially near ridge crests and roll-overs.

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

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Feb 2nd, 2014 4:00PM