As the strong March sun hits the cold snow, expect a rapid transition from dry powder to damp and wet conditions. In steep solar terrain, wet-loose avalanches could entrain a surprising amount of snow and run fast and far on the slick crusts beneath. Once the snow surface becomes damp and you start seeing rollerballs or pinwheels, it’s time to move off steep south-facing slopes. There is some uncertainty here since 700 mb (10,000') temperatures remain cold, but the March sun is strong.

Also keep an eye out for a greenhouse effect later this afternoon as thin, high clouds move in, which could make the snow surface damp on all aspects—not just the sunny slopes.

New Snow: Roughly 1-3 feet of low-density snow sits over slick crusts on many aspects from our rain event last week. As a result, dry-loose avalanches (sluffs) are running fast and far and could be large enough to bury a rider. We can also expect new snow soft-slab avalanches that fail within the storm snow due to density changes or a poor bond at the old/new snow interface. Use test slopes, slope cuts, and shovel tilt tests to see how the new snow is behaving.

Wind Drifted Snow: In upper-elevation terrain, look for smooth, rounded pillows of wind-drifted snow on the lee sides of ridges, sub-ridges, and other terrain features. These drifts often appear chalky, hollow, or textured compared to the surrounding snow.

The Dry January Layer (DJL) of facets is buried 2–4 feet deep beneath a hard slab of settled snow and crusts. Activity on this layer has been quiet since February 26th, and tests suggest it’s becoming stubborn to trigger. However, if it fails, it could still produce a large and dangerous avalanche. Steep, shallow, rocky upper elevation slopes facing W–N–E remain the most likely trigger points. Avalanches in the new snow could also step down into this deeper weak layer. Human-triggered avalanches remain possible.

UAC Forecaster. Trent Meisenheimer summarizes the current snowpack structure. This video is from Wednesday, March 4, before the storm.