What does "OVC" indicate about cloud coverage in a METAR report?

In a METAR report, "OVC" stands for "overcast," indicating that the sky is entirely covered by clouds. When "OVC" is present, it signifies that cloud cover is at 100%, meaning that there are no breaks or gaps in the cloud layer. This is significant for pilots and meteorologists because it affects visibility, flight operations, and weather predictions. Understanding cloud coverage is essential for assessing flying conditions, and "overcast" is particularly critical as it suggests a uniform cloud layer at a specific altitude without any breaks, directly impacting activities like instrument flying where visibility can be heavily influenced by cloud cover.

The other options refer to different types of cloud coverage; for example, the presence of "scattered" clouds would imply portions of the sky are clear, while "broken" clouds indicate a significant amount of sky covered but not completely, which is different from the "overcast" designation. Thus, "OVC" clearly delineates a state of full cloud coverage.