Archived

Avalanche Forecast

Jan 28th, 2015–Jan 29th, 2015

Alpine

3: Considerable

The avalanche danger rating in the alpine will be considerable

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Alpine

2: Moderate

The avalanche danger rating in the alpine will be moderate

Treeline

2: Moderate

The avalanche danger rating at treeline will be moderate

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Regions: South Rockies.

Spring conditions with overnight freezing and daytime warming.

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.

Avalanche 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