CAVOK is very common abbreviation in Aviation. It stand for Ceiling and Visibility is OK. The term CAVOK indicates the simultaneous occurrence of following meteorological conditions:

  • When the word CAVOK is used: Visibility, Clouds and present weather groups are omitted.
  • The code word CAVOK shall be included in place of the groups, when the following conditions occur simultaneously at the time of observation:
  • Visibility reported in the group VVVV is 10 km or more and criteria for inclusion of the group VNVNVNVNDV are not met;
  • No cloud below 1500 metres (5000 ft) or below the highest minimum sector altitude, whichever is greater, and no cumulonimbus and no towering cumulus;
  • No significant weather phenomena



NOTE:

Highest minimum sector altitude is defined as the lowest altitude which may be used under emergency conditions which will provide a minimum clearance of 300 metres (1000 ft) above all objects located in an area contained within a sector of a circle of 46 km (25 nautical miles) radius centred on a radio aid to navigation.