East Slopes North

Expect another relatively calm, mild day with partly sunny skies. While avalanches are unlikely, it's worth considering the chance of a cornice fall as they loom over previously wind-loaded slopes. Give cornices plenty of space and don't linger under them.

For Thursday, there are a few things to keep in mind: Cornices are very large and can fall without warning during periods of warm temperatures. Over the past week, there were a few rounds of wind slab avalanches that formed from west through southwesterly winds. While these slides are now difficult to trigger, it's worth keeping an eye out for wind-drifted slabs on leeward sides of ridges above 6,500ft. Steep southeast through southwesterly slopes will be warmed by the sun. While Thursday won't be the first warm, sunny day, and clouds will build, it's a good idea to keep an eye out for loose avalanches on steep sun-exposed slopes.

On Thursday, the skies will be partly sunny with clouds building by midday. Temperatures and light wind should be similar to Wednesday. On Wednesday, observers reported widespread surface hoar, 3-5mm in size. 

There's about 10-20" of snow that accumulated in the first week of February. Southerly aspects may have a thin crust on the surface. You may find another thin crust in the top 5-8" of recent snow. The last avalanche was reported on the 9th, when a few small wind slab avalanches were triggered on the leeward sides of ridges above 7,000ft. These were shallow, size D1-1.5, and involving recent snow. All occurred on the leeward. One may have run on a deeper crust, possibly from January 28th. 

The January 28th interface is buried 10-20" deep, and often shows up as a well-defined crust, though not everywhere. The crust has mostly been a non-issue. Last week (see photo below), there were a couple of larger, triggered wind slab avalanches that ran on this interface. At upper-elevations on north-east aspects, a couple of snow profiles revealed either a discernible (1cm) weak layer or large (1.5mm) well-preserved stellars immediately above the crust.  In a couple of profiles, the grains were small, rounding facets. Multiple other profiles in the Highway 20 corridor didn't find a weak layer or potentially problematic grains above the crust. While the 1/28 layer is likely a non-issue at the moment, it will be one to watch if future storms bring significant snow.