Avalanche Forecast

Issued: Mar 30th, 2015 10:26AM

The alpine rating is considerable, the treeline rating is moderate, and the below treeline rating is low. Known problems include Wind Slabs and Wet Slabs.

ghelgeson, Avalanche Canada

South Rockies.

Warmth is the main driver of avalanche hazard at the moment. Minimize your exposure to large slopes if the snowpack is becoming moist or wet.

Summary

Confidence

Poor

Weather Forecast

Tuesday: Freezing level starting around 2500m, lowering to 1500m by days end. Strong SW winds at treeline, Extreme SW winds at ridgetop. No significant precipitation expected.Wednesday: Freezing level hovering around 1500m. Partly cloudy skies all day. Moderate W winds at treeline, Strong W winds at treeline. No significant precipitation.Thursday: Freezing level holding around 1500m. Light variable winds at treeline, light W winds at ridgetop. No significant precipitation expected.

Avalanche Summary

On Monday our field team was in the Crown Mountain area where they noticed a few large slab avalanches on an extreme E/NE face that were likely triggered by cornice fall.Â On Saturday in the neighboring Lizard Range a size 2.5 avalanche that was likely triggered by cornice fall was observed, but the bulk of the observed activity was limited to minor sluffing and small loose wet avalanches.

Snowpack Summary

Sustained warm temperatures are helping to rapidly settle the snowpack at and below treeline. Ongoing SW winds have likely left lingering wind slabs on north through east facing features. The mid-March rain crust is down 30-60cm and has shown a good bond with snow above. Old persistent weak layers are still intact in the mid and lower snowpack. There is potential for these layers to wake up with sustained warming and/or significant rain. Recent cornice growth has been reported and these cornices may become fragile with daytime warming.

Problems

Wind Slabs

Watch for isolated wind slabs immediately below ridge crest. Wind slabs in motion may entrain loose snow gaining considerable mass as they move downhill. Large visor like cornices that overhang many ridge-tops are likely prone to failure.

Be cautious as you transition into wind affected terrain.>Do not travel on or below cornices Tuesday.>

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

Elevations: Alpine.

Likelihood

Possible

Expected Size

1 - 3

Wet Slabs

As the snowpack is subjected to ongoing significant warmth, the bond that loose snow, fresh wind slabs and small storm slabs have with the underlying crust should rapidly decay. Potentially large wet avalanches remain possible Tuesday.

.Avoid exposure to terrain traps where the consequences of loose wet avalanches could be very serious.>Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 5

Valid until: Mar 31st, 2015 2:00PM