I have seen some unusual fog conditions in my long life. I've driven through fog that would suddenly end, even if I was halfway across a long bridge.
One time I was driving in fog at night, and the bottom of the fog layer was about even with my rearview mirror. So my headlights were reflecting off the bottom of the layer. It was like I was driving through a horizontal slot. Then the fog would drop down to the hood level, and I had to slow down to a crawl.
Rivers do sometimes have different temperatures and wind conditions.
I have seen some unusual fog conditions in my long life. I've driven through fog that would suddenly end, even if I was halfway across a long bridge.
One time I was driving in fog at night, and the bottom of the fog layer was about even with my rearview mirror. So my headlights were reflecting off the bottom of the layer. It was like I was driving through a horizontal slot. Then the fog would drop down to the hood level, and I had to slow down to a crawl.
Rivers do sometimes have different temperatures and wind conditions.
Fog is basically a very low cloud.