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 3rd, 2021–Jan 4th, 2021

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

Regions

South Rockies.

Carefully evaluate your terrain choices, triggering storm slab avalanches remains a concern (especially at higher elevations). 

Confidence

Moderate - Uncertainty is due to the limited number of field observations.

Weather Forecast

SUNDAY NIGHT: Cloudy with some isolated flurries and up to 5 cm of snow, moderate west wind, temperatures drop to -8 C.

MONDAY: Cloudy with isolated flurries and up to 5 cm of new snow, moderate southwest wind, temperatures around -4 C.

TUESDAY: 5-15 cm of snow overnight then light flurries during the day, moderate west wind, temperatures around -6 C.

WEDNESDAY: Cloudy with some isolated flurries, moderate southwest wind, temperatures around -4 C.

Avalanche Summary

Several small skier triggered wind slab avalanche were reported over the weekend, but reports are limited. Based on the recent snowfall and wind, reactive storm slabs can likely still be found in steep in wind affected terrain. Triggering large persistent slab avalanches remains possible, even though few avalanches have been reported over the two weeks.

Snowpack Summary

The weekend's storm brought 10-30 cm of heavy snow that should stabilize relatively quickly, but could still be a problem in steep and wind affected terrain.

Weak layers of feather surface hoar and/or sugary faceted grains may be found above a hard melt-freeze crust around 50 to 100 cm deep. The most recent avalanche activity on these layers were reported on Dec 23 and 25.

The base of the snowpack consists of faceted grains and a hard melt-freeze crust from early-November. The most recent activity on this layer was on Dec 23, and it remains to be seen if the recent storm has increased the reactivity of this layer.

Terrain and Travel

  • Be alert to conditions that change with elevation and wind exposure.
  • Use ridges or ribs to avoid areas of wind loaded snow.
  • Avoid shallow, rocky areas where the snowpack transitions from thick to thin.
  • Avoid slopes that sound hollow or drum-like.
  • Be aware of the potential for large avalanches due to the presence of buried weak layers.

Problems

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.

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.