RUNWAY VISUAL RANGE. It is the maximum distance at which the runway, or the specified lights or markers delineating it, can be seen from a position above a specified point on its center line. This value is normally determined by visibility sensors located alongside and higher than the center line of the runway. RVR is calculated from visibility, ambient light level, and runway light intensity. Absolute humidity..., Backing..., Calm..., Daily mean..., Earthlight..., Fahrenheit temperature scale..., Gale..., Haboob..., Ice..., Jet streak..., Katabatic wind..., Lake effect snow..., Mackerel sky..., Nadir..., Obscuration..., Palmer drought index..., Quantitative precipitation forecast..., Radar..., Saffir..., Teleconnections..., Ultraviolet..., Valley breeze..., Walker circulation..., X-rays..., Year..., Zodiac....