Definition
An RVR (runway visual range) reading taken from a sensor positioned near the middle of the runway, reporting the horizontal distance a pilot can see down the runway from that midpoint location. RVR is reported in feet and is measured by transmissometers or forward-scatter sensors installed alongside the runway.
Plain English
How far you can see down the runway, measured from a sensor placed roughly in the middle of it. The number tells you the visibility at that specific spot, not the whole runway.
Context Anchor
Seen in low-visibility runway reports, weather information, and NOTAM contractions when runway visibility is reported by runway location.
Derivation
Runway visual range is a measured value, not a pilot estimate — 'visual range' simply means the distance a pilot can see. 'Midpoint' specifies which sensor along the runway produced this particular reading.
Why Pilots Care
Provides visibility data for the central runway section to support landing and takeoff decisions.
Grounding Statement
On a foggy runway, RVRM is the visibility reading from the middle measuring point, not a general guess for the whole airport.
Intuition Check
Midpoint does not mean the pilot is halfway down the runway. It means the RVR reading comes from equipment near the runway’s middle.
Example Sentence 1
Tower reported RVRT 2400, RVRM 1800, and RVRR 1600, indicating visibility was decreasing along the length of the runway.
Example Sentence 2
With a low RVRM the crew elected to hold until conditions improved.