What does "BKN///" signify in a METAR report?

The notation "BKN///" in a METAR report is used to indicate the presence of a broken cloud layer. The "BKN" stands for "broken," which specifically refers to a cloud cover that is between 5/8 and 7/8 of the sky covered by clouds, indicating that while there is a significant amount of cloud cover, there are also portions of the sky that remain clear.

The use of "///" that follows "BKN" signifies that there is no further information provided about the cloud's altitude or type. In this case, since the question pertains to the significance of "BKN///," it can include various altitudes, potentially indicating that the broken cloud layer is at an altitude lower than the airport elevation, which is crucial for pilots in assessing flight safety and planning landing approaches.

The correct interpretation focuses on the definition of "BKN" rather than specifics about other weather conditions or cloud characteristics that are not described in the METAR.