Although the trend shows improvement remember that the potential for triggering an avalanche is greatest at higher elevations due to recent heavy snowfall and strong winds.
Confidence
Fair - Due to the number of field observations
Weather Forecast
One last system is expected to cross the province tonight bringing moderate precipitation, high winds, and maintaining high freezing levels. We could see 5-10 cm by midday Friday. Freezing levels start near 2000 m but should drop to 1500 m late in the day. Winds are strong from the Southwest easing to light from the Northwest. The weekend looks much drier with a mix of sun and cloud. Freezing levels around 1000-1400 m on Saturday and 500-800 m on Sunday. Winds remain light.
Avalanche Summary
Reports from Wednesday include numerous loose wet slides up to size 2 from steep terrain below 2100 m throughout the region. There were also some new explosive triggered slabs up to size 2.5 from steep rocky terrain near Golden. One observer from the McMurdo Hut southwest of Golden reported seeing numerous avalanche crown lines and debris, particularly from alpine terrain.
Snowpack Summary
10-30 cm of moist or wet snow sits on a layer of surface hoar above 1800-2000 m. Below this the upper snowpack may be saturated. Another 15-20cm below this you may find a hard rain crust. In the Golden area this crust exists up to around 1600m, whereas in the south it is up to 2000m or higher. In total, last week's storm produced slabs up to 1m thick in the north of the region and around 60cm thick in the south. This slab sits on the mid-November weak layer (surface hoar, facets, and/or a crust). Below this you will likely find a 15-20cm thick layer of sugary facets, which is sitting on a solid rain crust from early November. The reactivity of these layers may be slowly diminishing, but they still warrant cautious consideration. Snowpack tests are getting hard pops and drops results, indicating the potential for large propagation and large avalanches.
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.
Loose Wet
Loose Wet avalanches are the release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry Avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.
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.