The second half of the first "paragraph" in all *.mis files, whether for the Campaign, SingleMission or others, is devoted to weather settings:
Fog=0
FogRand=0
Clouds=0
CloudsRand=0
Precip=0
PrecipRand=0
WindHeading=0
WindSpeed=5.000000
WindRand=0
WeatherRndInterval=5
SeaType=0
which does work well to set it for certain scenarios, but it still will "randomize" after the start, like the rest of the game. (Those are the "default" values.) I have something around here that has those listed and their value limits... only problem is - where??...
- The wind speed can go up to "15" (knots), the Heading to "359" (degrees), the "Interval" is (I think) hours, but the others are values of 1, 2, or 3, but I don't remember which is which... Basically "Low", "Medium" and "High"... I used those for the FotRSU Aleutians career patrols, so I've got the documentation for that somewhere - if you're interested... cdrsubron7 also knows how to do that. Check out his Single Missions for examples. Good stuff!