I think the main weather / terrain related thing I was thinking of was Foehn Wind and Rain shadow effects, Id go all out and type it up but I'd confuse myself too much so I shall snip it from the internet aha

'Rain Shadow - As air moves against a mountain range, it rises. As it rises it cools down. The cooling causes water vapor to condense and rain to form. As it passes over to the other side of the mountain, the air is more dry. It is characteristic of large mountain ranges to have wet and dry sides. For instance, the Sierra Nevada mountain range in California is relatively wet on the western, ocean-facing side and dry on its interior, eastern side. The wind created as the atmosphere rushes down the dry side of a mountain range create what are called "foehn-type" winds, such as the Santa Anas in Southern California. Many desert climates around the world are located beyond the dry sides of mountain ranges.'

Though I'm not sure as to how that sort of weather related issue would arise in Finland as I've not see the mountain ranges nor do I know of the altitude of them, More research is needed myself! :D

Foehn Wind is pretty much the same thing 'Winds of this type are also called "snow-eaters" for their ability to make snow melt or sublimate rapidly. This snow-removing ability is caused not only by warmer temperatures, but also the low relative humidity of the air mass having been stripped of moisture by orographic precipitation coming over the mountain(s).'

All this has blown my head...I havn't looked into weather for a while :)