Southern Madison

This wet loose avalanche is a great example of where they often occur. Rocks absorb extra heat from the sun and can quickly melt and destabilize the snow. Either move under areas like this early in the morning (as we did), or if you have to travel under them later in the day, move quickly.

This wet loose avalanche is a great example of where they often occur. Rocks absorb extra heat from the sun and can quickly melt and destabilize the snow. Either move under areas like this early in the morning (as we did), or if you have to travel under them later in the day, move quickly.

We rode into Tepee Basin along the headwall and up to the wilderness boundary. There had been a number of small releases of roller balls in steep rocky terrain but nothing got legs and ran. It would be hard to classify any of the activity, even as small wet loose avalanches. Crusts stayed robust and supportable throughout the day. 

There was 2-3” new snow at the bottom of the basin and 4–5 inches up near the wilderness boundary. Winds were calm, and there was no active wind loading. The new snow throughout the basin got moist during the heat of the day. North-facing slopes at upper elevations stayed cool and mostly dry. 

We had a nice late-season ride. Avalanches are unlikely under the current status quo. Today, the primary problem was isolated wind-slab instability in upper-wind-exposed terrain. Overall, there are safe avalanche conditions.

A significant warm-up or a significant pulse of snow would change the equation. At this point, it seems like most of the snow around has been transformed by warm temperatures over the last few weeks. I am more worried about new snow than a warm-up. 

We rode into the Taylor Fork, up to the weather station, and out towards the wilderness boundary. Temperatures were around 40 degrees at the car. There was a surficial refreeze last night with a skiff of graupel on top. With mostly sunny skies and calm winds the snow surface dampened quickly. 

We dug down on two sunny aspects (E-SE) and noted moist snow throughout the snowpack. In our first snowpit (9220', HS:108) we did not get notable test results (ECTX). We found that although faceted snow remains at the base of the snowpack, water has percolated down and moistened these basal layers. 

We also dug on a NW aspect (8800', HS:199) with no notable test results (ECTX). Moist snow exists in the upper 1.5' of the snowpack with dry snow to the ground. 

We noted no cracking or collapsing. We saw a good number of wet-loose avalanches on steep sunny slopes, but all were relatively small in width and depth.