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The continuous recorded broadcast of weather conditions at selected airfields. Volmet is updated every 30 min and, hence, the received broadcast may be slightly old. Elements of each broadcast are in the following order: surface wind, visibility, RVR (runway visual range) if applicable, weather, clouds, temperature, dew point, and QNH (atmospheric pressure reduced to sea-level pressure. The height of a place above mean sea level will be indicated when the QNH is set on the altimeter subscale). Nonessential words, such as surface wind and visibility, are not spoken. When CAVOK (cloud and visibility OK), the visibility must be more than 6 miles (10 km) and the clouds not lower than 5000 ft (1500 m), or below the minimum sector latitude, whichever is greater. Also, there should be no cumulonimbus clouds. Further, there should be no precipitation, thunder, shallow fog, or low-drifting snow. The surface winds, temperature, dew point, and QNH will continue to be broadcast.
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