What classifies as “variable” winds

January, 17, 2022 by

In the METAR for an airport you may see VRB or V listed in the meteorologic information. The definition can vary by country, but there is a standardized definition put out by the International Civil Aviation Organization.

V: More than 6 km/h and variation less than 180°. Mean wind direction and variation. Annex 3, § 4.1.5.2:

“1) when the total variation is 60° or more and less than 180° and the wind speed is 6 km/h (3 kt) or more, such directional variations shall be reported as the two extreme directions between which the surface wind has varied”

E.g. 31015G27KT 280V350.

VRB: Less than 6 km/h or variation more than 180°. No mean wind direction. Annex 3, § 4.1.5.2:

“2) when the total variation is 60° or more and less than 180° and the wind speed is less than 6 km/h (3 kt), the wind direction shall be reported as variable with no mean wind direction; or

3) when the total variation is 180° or more, the wind direction shall be reported as variable with no mean wind direction”

E.g. VRB02KT

Kyle Boas is the Founder of the IFATC Education Group. He is an IFATC Supervisor and Infinite Flight Appeals team member. — More