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 28th, 2019–Jan 29th, 2019

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

Regions

South Columbia.

Manage wind slabs by paying attention to how the snow feels underneath your skis/track, and backing off where it feels stiff. Increase your caution at and below treeline, buried surface hoar has been especially touchy between 1400 & 1800 m.

Confidence

Moderate - Wind effect is extremely variable

Weather Forecast

High pressure, cold temperatures and clear skies should allow for great travel and visibility Tuesday. Cloud cover starts to build back in Wednesday ahead of two storm pulses that should deliver a bit of snow beginning on Friday.MONDAY NIGHT: Freezing level at valley bottom, light northerly wind, no precipitation expected.TUESDAY: Clear skies, freezing level at valley bottom, light variable wind, no precipitation expected.WEDNESDAY: Broken cloud cover, freezing level at valley bottom, mostly light variable wind with moderate northwest wind at ridgetop, trace of precipitation possible.THURSDAY: Broken cloud cover, freezing level at valley bottom creeping up towards 1000 m in the afternoon, light variable wind, 1 to 3 cm of snow possible.

Avalanche Summary

On Sunday wind slabs averaging size 1 to 1.5 failed naturally and were sensitive to human triggering on all aspects between 1600 and 2600 m. One hard slab was remote triggered by a skier in the flats 50 m away from the subsequent avalanche, the wind slab then broke above the skier on a northeast facing feature at 2400 m. On Saturday wind slab avalanches to size 2 were reported from north, northeast, east, southeast and southwest facing features between 1950 and 2600 m. Wet loose avalanches to size 2 were also reported from south facing terrain.Several rider-triggered persistent slab avalanches up to size 2 were reported last week. The persistent slab avalanches were most prevalent between approximately 1200 and 1800 m, although some were noted at higher elevations, including into the alpine. Check out this MIN report for a great overview of conditions including photos.

Snowpack Summary

Saturday delivered warmth and strong to extreme wind out of the west, south, southwest and northwest. This left a crust up to 3 cm thick on steep south and some west facing aspects and redistributed quite a bit of snow into wind slabs in lee features at and above treeline. The warmth also allowed 25 to 45 cm of snow to continue to consolidate above the mid-January persistent weak layer (PWL). This PWL is made up of large surface hoar that is most prevalent at and below treeline, with enhanced reactivity noted between 1400 and 1800 m. On steep solar aspects this interface presents as a crust, there may be locations where the surface hoar actually sits on the crust.The middle and lower portions of the snowpack are generally well-settled and strong.

Problems

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.

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.