What is a critical element to include when issuing landing instructions during low visibility?

When issuing landing instructions during low visibility, it is essential to include ceiling and visibility information if it is below Visual Flight Rules (VFR). This information is critical because pilots need to have a clear understanding of the current weather conditions to make informed decisions regarding their approach and landing. Low visibility can significantly impact the pilot's ability to see the runway and other critical features around the airport, thus enhancing their situational awareness and safety.

By providing ceiling and visibility data, air traffic controllers equip pilots with the necessary information to assess their capability for a safe landing under those conditions. It helps them determine whether to continue their approach, go around, or divert to an alternate airport if the conditions are too poor for a safe landing. Including these details is a standard safety practice and an integral aspect of effective communication between air traffic control and pilots, especially in challenging weather scenarios.