What does the term "ceiling" refer to in meteorological reports?

In meteorological reports, the term "ceiling" specifically refers to the altitude of the lowest layer of clouds above the ground level that is either broken or overcast. This measurement is crucial for aviation as it directly impacts flight operations, particularly during takeoff and landing phases. Pilots rely on knowledge of the ceiling to determine whether they can safely navigate and operate their aircraft under visual flight rules (VFR) or must adhere to instrument flight rules (IFR). Understanding the ceiling helps in assessing weather conditions, allowing for better decision-making regarding flight plans and approaches to airports.