Abrupt haze or fog problem

I'm seeing the same thing with Real Weather. I will be flying along in scattered blue conditions and when I get near an airport where low vis. is reported, wham. I suddenly look like I am in overcast conditions. I fly a little past the airport and I am suddenly back into blue sky conditions. The low vis. comes on with no prior warning. You can be looking ahead at a mountain range and suddenly you can't see it. I thought with the new weather engine, distant weather systems were supposed to be visible prior to entering them? Is there a setting I'm missing. I have vis. set to 60mi and cloud draw set to 60mi.