Avalanche Forecast

Issued: Jan 28th, 2015 7:53AM

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

triley, Avalanche Canada

South Rockies.

Spring conditions with overnight freezing and daytime warming.

Summary

Confidence

Fair - Timing or intensity of solar radiation is uncertain on Thursday

Weather Forecast

The freezing level should drop to valley bottoms overnight, and then rise back up to about 1500 metres during the day. Expect continued sunny skies and light winds during the day on Thursday. We should see another good re-freeze to valley bottoms overnight and into Friday morning as the cooling continues. More sun and light winds on Friday. Saturday should be cooler with cloud and moderate Southwest winds developing in the morning, and light precipitation starting overnight.

Avalanche Summary

No new avalanches reported

Snowpack Summary

The cool down has started, with freezing levels dropping down to valley bottoms. We are in a spring like diurnal melt-freeze cycle that should cap the snowpack with a strong crust by the end of the forecast period. Record warm temperatures may have resulted in moist snow and an isothermal snowpack at lower elevations on Monday. High freezing levels (above mountain tops) have settled the near surface snow which overlies a rain crust to 1900m, facets, and/or surface hoar. The mid-December crust/facet layer is down 40-80cm. There is not much snow left below 1600 metres elevation due to the prolonged warm weather and spring like conditions.

Problems

Deep Persistent Slabs

Very warm daytime temperatures and high freezing levels may result in deep persistent slab avalanches releasing naturally from strong solar radiation or cornice falls, and continuing to be sensitive to human triggers.

Avoid convexities or areas with a thin or variable snowpack where triggering could be more likely.>Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet.>

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible

Expected Size

2 - 5

Loose Wet

Forecast periods of strong solar radiation may result in continued moist or wet loose snow avalanches.

Minimize exposure to sun exposed slopes when the solar radiation is strong.>Cornices become weak with heating, so give them a wide berth.>

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

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 4

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