FOG in the YABBA VALLEY
About 5kms upstream (to left of picture) there is an irrigation dam, Lake Borumba, and it increases the humidity in the valley. Add to that a gentle katabatic air flow that descends from the plateau to the west, and flows down the valley at night. This katabatic flow of air distributes the fog along the main axis of the valley as far as Imbil (11kms), quite often. At Imbil, the valley opens out to a plain, and the fog disperses.
But, there are many times especially in winter, when the whole of the valley can be filled with fog due to temperature inversion, and then the plains beyond Imbil are shrouded in heavy fog.
In this summer photo, there is no fog in the side valleys (foreground, for example) for this is the slow katabatic airflow moving the high humidity from the lake, down the valley axis.