Avalanche Forecast
Issued: Dec 12th, 2011 8:37AM
The alpine rating is Wind Slabs and Storm Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeSummary
Confidence
Fair - Forecast snowfall amounts are uncertain on Tuesday
Weather Forecast
Tuesday: We could wake up to 10-15cm of new snow. Through the day we may see up to another 10cm. Ridgetop winds will be strong from the south west. Treeline temperatures near -5, with freezing levels at valley bottom. Wednesday/ Thursday: A ridge will rebuild over the area bringing a mix of sun and cloud, with more snow expected later in the week.
Avalanche Summary
One natural size 2.5 was reported on a steep NE aspect at 1200m failing to ground. No additional information on this avalanche. Expect avalanche activity with current conditions and forecast weather.
Snowpack Summary
New snow and wind over the next 32 hrs will add an additional load to the current snowpack. The upper snowpack consists of a variety of snow surfaces. The region did receive up to 20cm of snow early in weekend which produced sluffing in steeper terrain features. It also buried a variety of snow surfaces including surface hoar, a melt freeze crust, and facets (sugary snow). Most operations in the region have reported large surface hoar (feathery type snow crystal) that is sitting on a thick melt-freeze crust. This crust is up to 20cm in thickness and extends up to alpine elevations in the south, and around 1000m in the north. A strong temperature gradient in the top 30cm was reported to be faceting snow below the surface crust. The mid and lower snowpack are generally well settled and strong. My main concerns are new wind slab formation on lee slopes. With the strong ridge top winds you can expect some wind slabs lower on slopes, or found in unsuspecting places. Storm slabs may also be an issue if they reach threshold over the weak buried snow surfaces. They can run fast, and far.
Problems
Wind Slabs
Aspects: North, North East, East.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Storm Slabs
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Dec 13th, 2011 8:00AM