Archived

Avalanche Forecast

Mar 24th, 2013–Mar 25th, 2013

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

2: Moderate

The avalanche danger rating below treeline will be moderate

Regions: Jasper.

Good overnight freeze is occurring; however, the sun packs a punch. The danger will increase in the afternoons at all elevations particularly on South aspects, gullies, and sun affected bowls. Gauge the amount of overnight freeze to start your day.

Weather Forecast

Monday to Wednesday will be clear skies, strong diurnal temperature fluctuation, and light W to NW winds. Freezing level is incrementally increasing each day this week. Monday it will be 1700m, Tuesday 1800m, and clouds on Tuesday evening may prevent a good overnight freeze starting the day off warm for Wednesday.

Snowpack Summary

A variable thick slab exists in alpine and treeline locations on a variety of aspects. It is over a strong midpack except in shallow locations where you could trigger basal facets or depth hoar weakness at the ground. At treeline in south facing terrain, their is a suncrust 80 cm deep. Strong diurnal temperature fluctuations have helped stability.Â

Avalanche Summary

No Sunday patrol. Nothing new noted on Saturday's Icefield's patrol with good visibility. A size 3 noted on Friday off Indian ridge main peak up Whistler creek scrubbing to ground, cornice fall trigger, and ran far. Thursday in Shangrila a size 3 was triggered by cornice fall in the afternoon heat, scrubbed to ground, 2m crown, and ran full path.

Confidence

Freezing levels are uncertain

Avalanche Problems

Deep Persistent Slabs

The March 13 90cm of snow has melded with the snowpack making for a deep persistent slab. North and South winds make it present on a variety of aspects overlying weak basal facets. Cornice failures can trigger this in a big way.

Choose the deepest and strongest snowpack areas on your run.Avoid shallow snowpack areas where triggering is more likely.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Possible

Expected Size: 2 - 3

Cornices

Cornices will become increasingly prone to failure as the days get warmer. They are a hazard in themselves plus their failure is a large trigger which may initiate large avalanches potentially running full path. Watch what's overhead.

Pay attention to overhead hazards like cornices.Extra caution needed around cornices with current conditions.

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

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 2 - 3