Avalanche Forecast

Issued: Mar 17th, 2013 4:20PM

The alpine rating is considerable, the treeline rating is moderate, and the below treeline rating is low. Known problems include Storm Slabs and Loose Dry.

garth lemke, Parks Canada

Jasper.

Avalanche danger will increase if sun comes out. The trend will be cold nights followed by daytime heating.

Summary

Weather Forecast

Monday will be flurries with potentially 10-15cm Sunday night to Monday night, seasonal temperatures, and possibly 75km/hr West winds at 3000m. Tuesday will be sunny, rising freezing levels from the sun and calm winds. Wednesday will bring a weak pulse of snow and the freezing level will rise to 1500m.

Snowpack Summary

Soft slabs have formed on exposed treeline locations and above from Saturday nights strong North winds. Expect reverse loading patterns. 90+cm of snow has fallen since Wednesday and this was our first real wind. At treeline, soft slabs rest on a thin suncrust buried 80 cm deep in exposed south facing terrain. Snow below treeline is unconsolidated.

Avalanche Summary

Maligne and Icefields patrolled today with 100% visibility. A few size 3 storm slab avalanches have run on large planar alpine slopes. They appear to be initiating in lower start zones around 2500m. Numerous loose solar sluffs to size 2 noted mainly on SW-NW aspects with a few on East aspects. Natural activity was increasing with solar punch.

Confidence

Timing or intensity of solar radiation is uncertain on Tuesday

Problems

Storm Slabs

10-20 cm of snow arrived last night with steady strong N winds. 80-100cm cm has fallen since Wednesday. This was the first real wind and many slopes appear to have a soft slab at exposed treeline and alpine locations. Reverse loading occurred.

Be careful with wind loaded pockets while approaching and climbing ice routes.Avoid travelling in areas that have been reverse loaded by winds.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 3

Loose Dry

There remains 20-50 cm of unconsolidated storm snow on and above local ice climbs. This snow is susceptible to solar, wind and human triggering forming loose snow avalanches of significant mass. Enough to knock climbers or skiers off their route.

Avoid travelling on ledges and cliffs where sluffing may have severe consequences.Finish ice climbs early in the day before the temperature rises.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2

Valid until: Mar 18th, 2013 4:00PM