08/04/2026
Snowpack at Castaños - 1% liquid water moisture and sub-zero temperatures
The snowpack in Corredor del Arroyo Pehuenche grew in both depth and water content
during July. South-facing slopes above 2300 meters have now reached 200 cm of snow
depth and have more than 500 mm of snow water equivalent (SWE). The snowpack is quite
dense, moist, and at temperatures near zero. Unlike other seasons, it doesn’t have the
usual cold content you’d expect in the Andes mountain crest of Corredor Arroyo
Pehuenche. This is because of some unusually warm storms, cloudy weather that doesn’t
let the snow cool down through infrared radiation, as well and strong warm wind events.
On Monday, August 3rd, the snowpack at 2450 meters appeared to have active liquid
water capillary flow with sub zero temperatures. The moist content was estimated at no
more than 1% level.
As the capillary flow transient state finishes, the freezing of the liquid water will slightly
raise the temperature due to latent heat as it changes state. And temperatures at the -2
degrees celsius at 20 cm through 60 cm depth should rise to -1 degrees, or possible reach
0 degrees, reaching temps equal to the snow surface and the lower meter of snowpack
closest to the ground.
The moisture in the snow is making the crystals rounder (rounding) and stick together
(sintering) faster, which means the snow is settling down quicker (settlement). We only
saw two recent storm layers that showed reactivity, but it shouldn’t last more than a few
days.
Early July another atmospheric river with rain at all elevations at elevation Corredor del
Arroyo Pehuenche destroyed the extensive basal facet layers at all elevations and aspects.
So far we have benefited from nature acts to take care of an unstable snowpack, with the
trade-off of lower ski quality warm snow.
As we look ahead, a warm snowpack with a lot of heat capacity can help bond new snow to
the old windy surfaces. But, it could also turn out to be a bit of a problem if cold snow falls,
making the old and new surfaces prone to facet metamorphism, increasing the chances of
facets forming at storm interfaces. We’ll just have to wait and see what Mother Nature
decides to do!
