Dashboard Regions Weather Stations Radar Alerts Glossary
Contact About
Log In

Register for an account and never miss a forecast again!

Register

Avalanche Forecast

Archived

Mar 14th, 2014–Mar 15th, 2014

Alpine
Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches possible, human triggered probable.
Below Treeline
Natural avalanches unlikely, human triggered possible.
Alpine
Natural and human triggered avalanches likely.
Treeline
Natural and human triggered avalanches likely.
Below Treeline
Natural avalanches possible, human triggered probable.
Alpine
Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches possible, human triggered probable.
Below Treeline
Natural avalanches possible, human triggered probable.

Regions

South Columbia.

You don't often see three problems in a forecast, but we don't often deal with a snowpack this complex. Professionals are running a tight and conservative ship right now, I recommend that you do the same.

Confidence

Fair - Timing, track, or intensity of incoming weather system is uncertain

Weather Forecast

Synopsis: Sunny skies are great and all, but we're transitioning back into winter this weekend. Saturday offers cloud cover, but we shouldn't see much precip until late in the day when it begins to snow and blow out of the SW. Snow should continue through the night and into Sunday before tapering off in the wee hours of Monday morning. At that time the flow switches to the NW and we should see some ridging build in early next week.(If you see this format X - (Y) - Z Then X - Z shows the probable range with Y being my best guess.)Saturday: Freezing Level: 1300m - (1500m) - 1800m; Precip: 2:8mm - 2:10cm (mainly late in the day); Wind: Light, SWSaturday Night: Freezing Level: 900m - (1500m) - 1800m; Precip: 8:16mm - 5:25cm; Treeline Wind: Moderate, SW | Extreme SW at ridgetop.Sunday: Freezing Level: 1000m - (1300m) - 1700m; Precip: 4:7mm - 5:15cm; Treeline Wind: Moderate, SW | Extreme SW at ridgetop.Monday: Freezing Level: 1050m - 1500m; Precip: 0:3mm - 0:5cm; Treeline Wind: Light, W

Avalanche Summary

On Thursday explosive control produced avalanches to size 3 on both SE & NE facing slopes in upper treeline and alpine elevations. A skier remote triggered a size 3 avalanche from 100m away on a NE facing slope at 2200m. The avalanche was triggered from low angle terrain and resulted in a very large avalanche with a crown up to 150cm in depth. This is just one more entry on a spooky list of rider triggered avalanches from the last week.On Monday a splitboarder triggered a size 2.5 storm slab on a west aspect in the Revelstoke area. No injuries were reported. Also on Monday a vehicle remotely triggered a size 2.5 slab avalanche on the February 10th interface in the SE corner of the region. Last Saturday's avalanche fatality occurred in the Keefer Lake area northeast of Cherryville. The avalanche, which occurred in a cut block at about 1700m, involved 3 sledders who were in a party of 6. Two of the men were able to inflate their airbags and were partially buried. The deceased was reportedly not able to inflate his airbag, and was buried approximately 5m below the surface.While not in this region, it's worth taking a look at last weekends incident from the Cariboos.

Snowpack Summary

The surface is currently a mix of 3 - 6mm surface hoar and crust. Last weeks storm snow has settled into a 50 - 100 cm slab that rests on the early March interface consisting of small grained surface hoar in sheltered areas and a sun crust on solar aspects. In upper elevation wind exposed terrain the new snow has been pushed into deep wind slabs by moderate SW winds.The last week featured an average daytime freezing level around 1800m which resulted in a daily melt freeze cycle that left many features wet and sloppy by the afternoon. This setup resulted in some serious incidents recently.Ridgetop cornices remain large and unsupported.The February 10th surface hoar/facet/crust combo is 80cm - 250cm below the snow surface and widespread throughout the region. Surface avalanches in motion and cornice fall still have the potential to initiate an avalanche on this deeply buried weak layer. Remote triggering on this layer is ongoing. The mid and lower snowpack are strong and well consolidated.

Problems

Deep Persistent Slabs

Deep Persistent Slab avalanches are the release of a thick cohesive layer of hard snow (a slab), when the bond breaks between the slab and an underlying persistent weak layer deep in the snowpack. The most common persistent weak layers involved in deep, persistent slabs are depth hoar or facets surrounding a deeply buried crust. Deep Persistent Slabs are typically hard to trigger, are very destructive and dangerous due to the large mass of snow involved, and can persist for months once developed. They are often triggered from areas where the snow is shallow and weak, and are particularly difficult to forecast for and manage.

Persistent Slabs

Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.

Storm Slabs

Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.