The Temperature/Dewpoint was 6C/10C ( 42.8 DegF/50.0 DegF).
The current Temperature/Dewpoint SPREAD was 7.2 Deg in the NEGATIVE direction, well B E L O W the temperature at which the air would become
saturated and fog would form! Then...if there were flat valleys or streams, HEAVY fog would have formed faster than the wind could sweep away.