No there is no such option in sh3 commander, there is sh3 weather program but I don't use that.
Tested it by loading up my IIa savegame, it was good weather when I saved, remained unchanged for 48 hours, then it turned for the worse, high winds and such, but since I was on my way home that was no problem.
the weatherstate is fixed for 48 hours after loading up the game, after that it can change, sometimes fairly rapidly, sometimes not....