If the satellite photos were taken when snow was on the ground there is nothing that is going to fix this right now until Asobo replaces the satellite image with no snow on the ground. New Meteoblue data isn’t going to fix that either.
If you are talking about the generated snow that is placed there by the sim then that’s a bug they will have to fix in the data. I am not familiar with this area myself so I don’t know what the problem is. If you load clear static weather and there is still snow on the ground then it’s in the satellite photo and this can’t be fixed without updating to an image taken in the summer months.