prevailing visibility


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prevailing visibility

[pri′vāl·iŋ ‚viz·ə′bil·əd·ē]
(meteorology)
In United States weather observing practice, the greatest horizontal visibility equaled or surpassed throughout half of the horizon circle; in the case of rapidly varying conditions, it is the average of the prevailing visibility while the observation is being taken.

prevailing visibility

The horizontal distance at which targets of known distance are visible over half the horizon. It is determined by viewing dark objects against the horizon sky by day and moderate-intensity unfocused lights by night. The half of the horizon need not be a continuous half.
References in periodicals archive ?
Prevailing visibility, which is the primary visibility measurement we see in METAR reports, is the maximum visibility figure valid for half of all directions around an observer.
The prevailing visibility dropped to one mile with intermittent rain, with winds increasing to 35 knots.
Take into account your tackle, bait, hook or lure, the prevailing visibility of the water, the species you are targeting, and the style of fishing you have planned.
They would first determine prevailing visibility, the minimum distance that objects can be identified and recognized throughout at least half of the horizon circle surrounding the station.
To mitigate the risks in an environment characterized by marginal weather and rapid changes in prevailing visibility, we follow rules and SOPs put in place by OpNav 3710 and higher headquarters.
The greatest horizontal visibility equaled or exceeded throughout at least half the circle is prevailing visibility. The circle need not be continuous; there could be obstacles in the way.
Visibility is more properly defined as "prevailing visibility." This is the shortest distance at which objects or bright lights can be seen and distinguished.
Military prevailing visibility is stated in meters rather than statue miles and values greater than 7 statute miles are stated as 9999.
Once the prevailing visibility drops to a mile or less, or the RVR displays a value at or below 6000 feet, controllers must issue current RVR to each aircraft using the relevant runway.
While the tower (or ASOS/AWOS) reports prevailing visibility for the airport, SMGCS-equipped airports measure the actual visibility at one or more places along one or more runways.
I asked ATC to query the facility if that was the prevailing visibility or transitory.