Avalanche Forecast

Issued: Dec 30th, 2015 8:48AM

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

ghelgeson, Avalanche Canada

South Rockies.

Wind slabs continue to be a concern at higher elevations. In some areas wind slabs may be sitting on a weak layer of facetted snow.

Summary

Confidence

Moderate - Freezing levels are uncertain on Friday

Weather Forecast

The recent stormy pattern that December begat is history, and we enter a new meteorological regime marked by remarkable stability and an almost complete void of storminess over B.C for the next week. Warm Pacific air riding over the entrenched Arctic airmass currently in place is expected to lead to warm alpine temperatures beginning Friday. THURSDAY: Freezing level at valley bottom, light variable winds, no precipitation. FRIDAY: Freezing level at valley bottom, above freezing temperatures between 1700 and 3000m, no precipitation. SATURDAY: Freezing level at valley bottom, above freezing temperatures between 1700 and 2700m, no precipitation.

Avalanche Summary

No new avalanche activity to report from the last 3 days.. On Sunday a group of sledders triggered or remotely triggered a slab avalanche size 2.0 about 2km south of Castle Mountain that resulted in one rider deploying his airbag and being partially buried. More details here: http://bit.ly/1TqhuQf

Snowpack Summary

Our field team was in the Smith Basin and Mear Lakes area on Monday. They reported 110-150 cm of snow on the ground at 2250 metres. There was 40 cm of loose dry snow above 10 cm of cold facets that produced variable moderate to hard shears in snowpack tests. The storm snow is unconsolidated and the field team remarked that even the small larch trees still had new snow on them; evidence of very little in the way of wind. They did not get direct alpine observations, but suspect that there may be more wind effect at higher elevations. These observations are consistent with reports from near Castle Mountain with storm snow above facets.

Problems

Wind Slabs

Wind slabs continue to be a problem where the recent storm snow was transported into deep pockets. In some areas these wind slabs may be stiff and may also be sitting on a weak layer of cold faceted snow.

Avoid freshly wind loaded features.>Avoid travelling in areas that have been reverse loaded by winds.>Use ridges or ribs to avoid pockets of wind loaded snow.>

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

Elevations: Alpine.

Likelihood

Possible - Likely

Expected Size

1 - 3

Cornices

Newly formed cornices may be fragile and easily triggered by traveling nearby.

Extra caution needed around cornices with current conditions.>Give cornices a wide berth when travelling on or below ridges.>

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

Elevations: Alpine.

Likelihood

Possible - Likely

Expected Size

1 - 2

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