Avalanche Forecast
Issued: Apr 20th, 2019 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs, Persistent Slabs and Loose Wet.
jasper snow safety,
Parks Canada
Up to 30cm of recent heavy snow with winds has activated the problems with continuing natural activity. Give the new snow a couple of days to settle and bond.
Summary
Weather Forecast
The next couple of days will be generally sun and cloud, no new snow except for maybe a little on Monday and Tuesday, and rising incrementally freezing levels. A wind event may arrive Monday evening with 70km/hr winds.
Snowpack Summary
Moderate winds, mild temperatures and 30cm of new heavy snow Thursday night created widespread slabs in the alpine and into tree line. It rained at lower elevations making isothermal conditions where enough snow exists. A persistent facet weak layer down 40-70cm exists in some locations.
Avalanche Summary
Saturday's field patrol observed loose wet up to size 2, persistent slabs to size 3 on mainly NE aspects in alpine, and also thin windslabs size 2-2.5 E aspects. Yesterday there was a natural cycle with the recent 30cm storm. Friday's avalanche control on Highway 93 produced several wind slab avalanches up to size 2 and some stepped down.
Confidence
Problems
Wind Slabs
Up to 30cm of new heavy snow has built reactive slabs. They vary in depth from 20cm to up 60cm thick depending on loading patterns.
- Use caution in lee areas in the alpine and treeline. Recent storm snow has formed wind slabs.
- The new snow will require several days to settle and stabilize.
Aspects: North, North East, East, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
The new snow load initiated a natural cycle on this problem the past couple of days. Give it a few days to settle. Consequences would be severe if initiated.
- If triggered the loose wet sluffs may step down to deeper layers resulting in large avalanches.
Aspects: North, North East, East, North West.
Elevations: Alpine.
Likelihood
Expected Size
Loose Wet
Activity increases with afternoon warming and less of an overnight freeze. Caution around terrain traps where small slides would have severe consequences.
- Use extra caution on solar slopes or if the snow is moist or wet.
- Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.
Aspects: All aspects.
Elevations: Below Treeline.
Likelihood
Expected Size
Valid until: Apr 21st, 2019 4:00PM
