She stared into the early darkness of a thick cloud cover.
Daylight was making a feeble attempt to break through the heavy cloud cover.
The short wavelength limit is due to atmospheric absorption and depends on atmospheric composition such as the presence of cloud cover.
Of course, the entire event is rendered invisible by thick cloud cover.
In spite of the wind cloud cover was only 3 oktas with the passing clouds scudding rapidly across the sky.
