Slitherine

I am just curious if this is by intention or just by chance: In the Moscow41 mission of the basic campaign, the wheather forecast indicator rarely shows the real conditions in the next turn (although this should be the case up to 80%). I think this is intended to be more realistic for certain scenarios; i.e. for Moscow41 -> mud and snow. to be clear: I dont complain!!!!!
On the other hand this seems not to be entirely consistent for all campaign missions.
Does anybody know more about this?

I guess it's just bad luck. The number of turns of a scenario is too small to have a relevant conclusion from a statistic point of view.