Grand Mesa

Hot with high thin clouds and generally calm.

The current snowpack ranged from 28 inches (70 cm) to about 48 inches (120 cm). The snow near the ground is faceted (or sugar-like), and there is a cohesive slab on top of this that is supportable to snowmobiles and feet. It takes a lot of load to break through this layer, but the poor snowpack structure still exists to trigger a dangerous avalanche on the right steep, unsupported north-facing slope. Normal signs of instability were not observed, but the weak layer persists below a cohesive slab. South-facing grassy and rocky areas are nearly melted out, creating navigation challenges, with only a couple of inches of slush and crusts resting on bare ground. Additionally, we found many open, difficult-to-cross creeks with steep snow banks.

On northeast facing terrain, there was an average height of snow between 60-85cm. I found one isolated roll over with a height of snow closer to 120cm. There are two melt freeze crust sitting above a pencil hard slab (see snow profile below). Snowpack tests on this aspect resulted in propagation in deep faceted layers. It is worth keeping an eye on this poor structure for wet avalanche issues as warming continues through the week.

Snow depth has reduced from 4.5' to 3.5' since February 22 at my roadside stake at Skyway.

Around a foot of new snow fell in this area, difficult to tell as the winds transported so much of the new snow, but this wind-drifted new snow has developed into a 4F to 1F hard (on the hand hardness scale) slab resting on top of a very concerning and poor snowpack structure. Measured 1.1 inches of SWE in the new snow near the summit of Williams Peak. The rest of the snowpack is composed of multiple weak layers of very well-developed facets that likely will remain a concern until spring melt-freeze cycles. Extended column tests (ECTs) had a combination of non-propagating failures on the uppermost facet layer and propagating failures on at least two other, deeper, weak layers with less than 10 taps consistently.

There was a thin sun/temperature crust on the south-facing and flat terrain near the Skyway weather station. This may limit the loading to the suspect locations like Cliffs #4. Ski penetration (PS 30 cm) was still through the soft slab, but this will likely change with the incoming storm.

The snowpack is fist hard on the hand hardness scale from top to bottom, save the "Grinch" crust in the middle from the rain event around the Christmas Holiday. This crust is the only component holding up the ski penetration, but it too has softened and is trending toward faceted grains. The smallest grain size I observed was 2mm!

The thick (3cm or 1 inch thick) rain crust from Christmas is now buried about 10 inches above the ground. Below the crust are well-developed facets and depth hoar down to the ground with clear ice columns from the rain event in December. Above the crust, the layers are generally faceted (weak, sugary snow), and your boot will penetrate to the crust layer when you step off the machine. The thick, supportable rain crust provides a good base, preventing snowmobiles from hitting smaller logs or rocks less than about a foot off the ground.

The "fairy dust" from Storm 10 (Jan 8 and 9) settled from a foot of snowfall to about 4 or 5 inches of snow overlying the large-grained surface hoar (1cm) buried by that storm. The surface hoar and the high snowfall rates resulted in some small loose dry avalanches that reached the northbound lane on state highway 65 during that storm 10. That surface hoar seems like it will mix in with the faceting snowpack here on the north side of the Grand Mesa. The Grinch Crust from rain on Christmas Day and buried by snowfall on December 28 is slowly faceting from below. I measured it at 2cm thick, whereas a week ago it was about 4 cm thick. Large chains of faceted grains are linked below the crust.

Light southerly winds with moderate gusts. Scattered and increasing cloud cover with temperatures in the low to mid 20's.

Nice day once you got out of the morning fog and up to Skyway. The temperature was in the low 30's with some increasing high cirrus.

There is a thick rain crust (1-3cm thick) about 4 to 6 inches beneath the snow surface. The crust is mostly supportable to the weight of a snowmobile but easy to break through by simply leaning onto one side of the slide and making the weight less distributed over a smaller surface area. Below the crust are well-developed facets and depth hoar down to the ground, and there are chains of facets developing on the bottom of the rain crust as well. The deepest snowpack we found was about 60cm deep. We measured 3.6 inches of Snow Water Equivalent (SWE) in a pit near Scales Lake Number Two, excluding the rain crust, which is a bit more than the nearby Mesa Lakes SNOTEL and a bit less than the Park Reservoir SNOTEL at 2.4 and 4.7 inches of SWE, respectively, both far below the 30-year median.