@srs-bsns Nothing seems to have changed in the snow calculator or the Surface classes of the biomes that use the 'Polar' surface, so I guess it has to be caused by some changes to the noise algorithms themselves?

Can you think of anything that changed that might be causing this? Maybe something got accidentally converted/cast when refactoring the noise classes?

Not a show-stopper if we can't fix this before the initial 1.12 release, but it would be good if we could get to the bottom of it.