[John Pancoast]

I have similar experiences so I just started using the stock envsim.act file.
Much better.
I know some had weeks long storms/fog/15m/s winds with it, but longest I've had is four days. Been using it awhile, really like it's variety of weather.
Stiebler's file is great work, but it makes the weather to good.

Try the stock file if you haven't already.