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

Jan 7th, 2012–Jan 8th, 2012

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

Regions

South Columbia.

Confidence

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

Weather Forecast

A polar warm front stalling north of the region will bring moderate to heavy precipitation to the surrounding areas Sunday. However, the South Columbia will largely be "protected" from the action by a lingering ridge of high pressure. I expect scattered flurries in the region Sunday with precipitation values in the 5 - 10 cm range. The western edge of the forecast region will likely receive a bit more. Freezing levels rise to 1500m or so Sunday as the warm front affects the area. The trailing cold front associated with the system moves in late Sunday/early Monday bringing lower freezing levels and another 5 -15 cm of snow. Expect strong SW winds at & above treeline Sunday with a daytime high of 0 C @ 1500 m.

Avalanche Summary

The new snow has been sluffing in steep terrain & a few natural avalanches to size 2.5 involving the new snow (likely wind affected) have been reported on almost all aspects at and above treeline.

Snowpack Summary

The region has received 30 - 70 cm of snow out of the latest storms. In some locations, this new snow rests on a buried surface hoar layer from Jan. 03. Strong SW winds have redistributed the new snow into wind slabs which can be found in varying thicknesses on NW through SE facing slopes. The mid-December surface hoar layer remains a concern and is now buried 90 - 150 cm below the surface. While fairly wide spread, it seems to be most sensitive on South through East facing aspects around treeline. In some locations a crust can be found from valley bottom up to about 1600 m that formed with the recent warm temperatures.

Problems

Wind Slabs

Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind 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.

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.