Avalanche Forecast

Issued: Mar 16th, 2017 8:13AM

The alpine rating is high, the treeline rating is high, and the below treeline rating is high. Known problems include Storm Slabs and Persistent Slabs.

ross campbell, Parks Canada

Glacier.

IT'S NOT OVER, with another pulse of large natural avalanche activity last night. The snow pack will need cooling temperatures before it can heal, which isn't forecasted until next week. Large destructive avalanches are still possible today.

Summary

Weather Forecast

A mix of sun and cloud with isolated flurries today. A slight cooling trend with FL lowering to 1200m, winds should back off into the mod range, currently they're strong gusting to extreme. On Saturday the FL will rise again as we get crushed by another low pressure system, bringing 40mm and strong winds.

Snowpack Summary

Intense loading last night, with significant precipitation (5mm+ an hour) and strong winds created new touchy storm and wind slabs. Yesterday we received 30-40mm of precipitation, with FL hovering near 2000m, these storm layers sit on the previous 60+ cm of HST from earlier this week. The late feb interface is now down 1-1.5m.

Avalanche Summary

Last Friday was the beginning of this long tenured natural avalanche cycle, peaking yesterday and last night with significant precipitation amounts, strong winds & warm temperatures. Yesterday we initiated 63 Artillery controlled avalanches to size 4, we saw 40+ naturals in the highway corridor to size 3. IT'S NOT OVER and on sat it'll peak again!

Confidence

Problems

Storm Slabs

Substantial snow and rain fell over the last 6 days! Rain on new snow then more new snow is a perfect combination for avalanches! Once commenced these storm slabs can step down to deeper layers in the snow pack, resulting in full depth avalanches.

If triggered the storm/wind slabs may step down to deeper layers resulting in large avalanches.The new snow will require several days to settle and stabilize.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Very Likely

Expected Size

2 - 4

Persistent Slabs

Rain soaked snow yesterday will have penetrated deep into the snowpack, lubricating the deeper persistent layers of concern. As the storm slabs fail above these layers it will easily step down to the Feb 28th interface and deeper.

Use conservative route selection, choose moderate angled and supported terrain with low consequence.Watch for whumpfing, hollow sounds, and shooting cracks.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

3 - 4

Valid until: Mar 17th, 2017 8:00AM