Temperature inversion at Uri Alps

Under normal circumstances, the air near the surface of the Earth is warmer than the air above it, as described usually by a constant temperature gradient. But during times of stable, high-pressure air conditions, colder air settles into mountain valleys, which creates the inversion.
The photo was taken next to Zahm Geissberg at about 2300 m.a.s.l. capturing Huetstock (Wild Geissberg, 2676m). Despite the altitude, mid-fall and coming sunset, there was sunny weather with the apparent temperature above 20 degrees of Celsius. Down there, in clouds, there was a snowstorm, with freezing temperatures below 0 Celsius. And there is no other way back than through these clouds.