Avalanche Forecast

Issued: Apr 25th, 2017 4:00PM

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

snow safety, Parks Canada

Banff Yoho Kootenay.

Even short solar inputs will increase the reactivity of the new snow. Watch for changing conditions through the day.

Summary

Weather Forecast

Clearing overnight with increased cloud cover Wednesday morning, more precipitation is forecasted with amount ranging from 5-10cm. Winds are expected to remain light in the alpine. Temperatures will hover around zero degrees for the valley with alpine temperature in the -5 to -10 range.

Snowpack Summary

20-40cm of new snow overnight with minimal winds Tuesday kept the storm snow light in the alpine, steep solar aspects and lower elevations did see settlement and moistening in the storm snow. The new snow sit over numerus melt freeze crust's on all aspects below 2300m and high alpine on solar. The basel weakness still persist at higher elevations.

Avalanche Summary

Numerus loose dry avalanches to size 1.5 have released in the storm snow, although no real slab has developed in the new snow, the storm interface is touchy and easy to trigger loose avalanches.

Confidence

Problems

Loose Wet

Brief solar input's or warmer then anticipated temperatures will rapidly moisten the new snow.

If triggered the loose wet sluffs may step down to deeper layers resulting in large avalanches.Pay attention to sluffing off cliffs and steep solar terrain, signs of a warming snowpack.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2

Deep Persistent Slabs

The snowpack is gaining strength, but the weak basal facets continue to produce sudden collapse results and can produce large avalanches with large triggers or heat. Stick to planar, supported slopes with a deeper snowpack when entering steep terrain

Pay attention to overhead hazards like cornices which could easily trigger the deep persistent slab.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 4

Loose Dry

Up to 40cm of new snow monday night has had little inputs from the wind, sun or warming temperatures at higher elevations. The new snow has stayed relatively dry and easy to trigger, causing loose avalanches that can entrain a lot of snow.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely - Very Likely

Expected Size

1 - 2

Valid until: Apr 26th, 2017 4:00PM