thanks for help, AlanSmithee.
I had the 'Bad weather gun' mod installed, that's why.
Like you said, i modified the wind/rain variables in my VIIC .cfg file :
I have lowered the wind to:12m/s and the rain factor to : 0,6.
This works pretty well for me because i can use the deck gun until high winds, and the guys put their coat not before a fairly descent rain, and can enjoy the added realism of the costumes.
The equation is like: Raincoats on = No Deck gun...