should be right approach, you’ll create weather sequences and then just blend them randomly. So make a sequence where it ALWAYS rains and then just blend at random times to that sequence. Do the same for fog/foggy, snow etc…
On a sidenote: i just wanted to download the latest version and noticed they removed all downlinks but for 4.13.2. Anyone else having that problem ? i got a version for 4.14 a downloaded a while ago but not sure why they removed all newer versions.