Avalanche Forecast

Issued: Mar 28th, 2015 10:04AM

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

ghelgeson, Avalanche Canada

South Rockies.

Warm temperatures and sunshine are the main drivers of avalanche hazard at the moment. Minimize your exposure to large slopes if the snowpack is becoming moist or wet.

Summary

Confidence

Poor - Due to the number of field observations

Weather Forecast

Sunday: Freezing level starting near 2000m, rising to about 2400m in by the end of the day. Strong SW winds at treeline, strong to extreme W winds at ridgetop. Potential periods of strong sun with intermittent cloud. No significant precipitation expected.Monday: Freezing level starting near 2300m, rising to 2600m in the afternoon. Moderate SW winds at treeline. Strong W/SW winds at ridgetop. Mostly clear skies. No significant precipitation expected.Tuesday: Freezing level starting at 2500m, lowering to 1500m by days end. Strong SW winds at treeline, Extreme SW winds at ridgetop. No significant precipitation expected.

Avalanche Summary

No recent observations. In the neighboring Lizard Range numerous loose wet avalanches and a few wet slabs were observed to size 2 on Friday. Our field team also reported continued widespread loose wet avalanches and wet slabs to size 2 that were entraining significant mass as they moved downhill.

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

Loose Wet

Loose wet activity is expected to persist with the bulk of the activity occurring below 2000m, periods of sun could initiate fresh rounds of loose wet activity at upper elevations too. Large droopy cornices are primed for failure at this time.

Extra caution needed around cornices as they become weak with daytime heating.>Avoid exposure to terrain traps where the consequences of a small avalanche could be serious.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Likely

Expected Size

1 - 3

Persistent Slabs

Continued warming and solar radiation could make deeper persistent weaknesses more susceptible to triggering, especially sun-exposed and thinly snow-covered slopes.

Space out and travel quickly through runout zones of avalanche paths.>Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.>Be aware of the potential for large, deep avalanches due to the presence of a buried crust/facet interface.>

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Valid until: Mar 29th, 2015 2:00PM