Avalanche Forecast
Issued: Mar 28th, 2021 3:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs and Cornices.
jcoulter,
Avalanche Canada
There is uncertainty with localized forecast snowfall amounts. A mix of recent storm snow and strong winds will likely combine to make slabs sensitive to human triggering on Monday. Be especially cautious transitioning into wind affected terrain and steer clear of cornices.
Summary
Confidence
Moderate - Uncertainty is due to the timing, track, & intensity of the incoming weather system.
Weather Forecast
There is some weather uncertainty. There are two opportunities for "enhanced" local precipitation amounts in various places in our vast region. The first chance comes with the strong south west flow into this evening. The second comes with the potential for localized convective activity with the passing of the cold front.
SUNDAY NIGHT - Flurries, 10-20 cm overnight / strong southwest wind switching to north west with passing of the cold front / alpine low temperature near -5 / freezing level dropping to valley bottom by morning.
MONDAY - Mainly cloudy with scattered flurries / light to moderate northwest wind / alpine high temperature near -4 / freezing level at valley bottom
TUESDAY - A mix of sun and cloud / moderate west wind / alpine high temperature near -6 / freezing level 1500 m
WEDNESDAY - Mostly clear / moderate south west wind / alpine high +4 /freezing level 2200 m
Avalanche Summary
On Sunday neighbouring forecast regions reported cracking on open wind affected slopes.
On Saturday there were wet loose avalanches on solar slopes reported in the region.
Glide cracks continue to grow. This serves as a great reminder to avoid slopes with glide cracks on them at all times. They are inherently unstable and can release at any time.
Snowpack Summary
By Monday expect 10-30 cm of recent storm snow over a variety of old surfaces such as crusts on all but north aspects in the alpine and treeline and crusts at all elevations below 1700 m.Â
Recent winds have switched from strong southwest to strong northerly so fresh and reactive wind slabs may be found on a variety of aspects in open terrain in the alpine and treeline.
Lower elevations are likely to be crusty and rugged when freezing levels drop Monday morning.
The mid-pack is firm and well settled. Some faceted snow and a decomposing melt-freeze crust can be found near the base of the snowpack.
Terrain and Travel
- Be especially cautious as you transition into wind affected terrain.
- Continue to make conservative terrain choices while the storm snow settles and stabilizes.
- Closely monitor how the new snow is bonding to the old surface.
- Pay attention to cornices and give them a wide berth when traveling on or below ridges.
Problems
Storm Slabs
With recent loading and continued wind, storm slabs are expected to stay reactive throughout the day, especially in wind loaded terrain.
Monitor the bond of the new snow to old surfaces before committing to any terrain with consequences.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Cornices
Recent strong southwest through northwest winds have been building fresh cornice growth.
Cornices falls can be a hazard on their own, and can also act as a trigger for avalanches on the slopes below.
Aspects: North, North East, East, South East, South, North West.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Mar 29th, 2021 4:00PM
