In METAR, what does "RVR" stand for?

"RVR" stands for "Runway Visual Range," which is a crucial metric used in aviation to assess the visibility conditions an aircraft may experience when approaching or landing on a runway. RVR provides pilots and air traffic controllers with information about how far ahead a pilot can see down the runway, particularly under low visibility conditions such as fog, heavy rain, or snow.

Runway Visual Range is measured using instruments that gauge the distance over which a pilot can see runway lighting and markings. This information helps to determine whether it is safe for aircraft to land and take off, as different runways may have varying RVR values depending on the weather conditions. Knowing RVR is vital for ensuring safe operations, especially for approaches that may require specific visibility minimums, such as precision and non-precision approaches.

Other choices, such as "Runoff Visual Rate," "Rapid Visibility Report," and "Relative Visibility Reading," do not correspond to established aviation terminology. These terms do not reflect any standard practice in aviation reporting or safety assessments regarding runway conditions, which further supports that "Runway Visual Range" is the accurate interpretation of RVR in the context of METARs.