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WIND
WINDDIRECTION quoted as either:
A. SINGLEMEANDIRECTION
B. TWOVALUES representing variation inwind directionwill begiven
whenever:
i the extremes inwind direction vary by 60° ormore; or
ii the variation is considered to be operationally significant (e.g. the
variation is less than 60°, but the variation from themean results is
either a downwind and/or significant cross-wind component on a
nominated runway).
C. VARIABLEwill be usedwhen the reportingof ameanwind direction is not
possible, such as:
i in lightwind conditions (3 kt or less); or
ii thewind is veering or backing by 180° ormore (e.g. passage of
thunderstorms, or localisedwind effect).
WINDSPEEDquoted as either:
A. CALM (less than 1 kt, eg ‘WINDCALM’);
B. SINGLEMAXIMUMVALUEwhenever theextremes betweenminimum
andmaximum are10 kt or less (e.g. ‘WIND250DEGREESMAXIMUM 25
KNOTS’);
C. TWOVALUESREPRESENTINGMINIMUMANDMAXIMUMVALUES
whenever the extremes inwind vary bymore than 10 kt (e.g. ’WIND250
DEGREESMINIMUM 15KNOTS,MAXIMUM28KNOTS’).
Note: When quoting awindwith variations in speed and direction, the above
criteriamay be varied in order to indicate the true cross-wind and/or
downwind.
Where thresholdwind analysers are installed, and thewind at the threshold
of a duty runway varies from that of the central wind analyser or the threshold
wind on the other duty runway by criteria specified for the revision of ATIS,
thresholdwindsmay be broadcast on theATIS; eg. THRESHOLDWIND
RUNWAY…(number),…/…, RUNWAY…(number),…/…
in-flight information
2 – f l i ght i nformat i on serv i ce