Avalanche Forecast

Issued: Feb 26th, 2014 4:00PM

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

snow safety, Parks Canada

Banff Yoho Kootenay.

The Feb 10 interface will heal, but its going to take some time. Its tempting to jump into bigger features with the good weather, but we still have low confidence in the current snowpack at treeline and above. SH

Summary

Weather Forecast

Freezing levels to 1800m on Thursday, light NW winds and a mix of sun and cloud. Alpine temperatures will be around -5C. Starting tomorrow night we will have a cooling trend with temperatures going to -30C or lower Friday afternoon into Saturday.

Snowpack Summary

30-40cm of settled storm snow sits on top of the Feb10th layer of facets,surface hoar, and on solar aspects a sun crust. Compression tests over the last 2 days in many areas range from easy to hard, sudden collapse at this interface. Slopes with a buried suncrust appear to be the most touchy. Some isolated wind slabs are present in the alpine.

Avalanche Summary

A natural sz. 2 occurred today due to an inversion and strong sun on a SE aspect above the ice climb Bourgeau right. This was 100m wide but did not go over the climb. Smaller slides to sz.1 on solar aspects at all elevations were seen mainly out of steep, rocky terrain. Explosive control on the Sunshine road produced limited results up to sz. 1.5.

Confidence

on Thursday

Problems

Persistent Slabs

The Feb.10 interface of weaker crystals is slow to gain strength. Slab properties above this layer are becoming stiffer, and human triggering is very possible. These seem to be the most touchy on solar aspects where there is a buried suncrust.

Dig down to find and test weak layers before committing to a line.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

1 - 3

Wind Slabs

These are becoming less reactive, but look for wind slabs in lees of alpine features and exposed areas.

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

Elevations: Alpine.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Valid until: Feb 27th, 2014 4:00PM