Webtag for Backing/Steady/Veering Wind?

[Buford T. Justice]

Would it be possible to have a webtag for these wind conditions? My understanding is:

If the wind changes in a counter-clockwise direction; it is backing.

If the wind changes in a clockwise direction; it is veering.

Steady means no change in direction.

[beteljuice]

If I remember correctly (and I found it a bit confusing then !) It is the trend over time (typically 4 hours) of change of wind direction AT ALTITUDE (ie. for an observer it would be indicated by cloud direction)

... and I never could find out if (forecast-wise) the reasoning was reversed South of the equator !

(I seem to remember finding just one snippet that said if the 'ground' winds were >20 mph they usually followed the higher altitude winds)

[steve]

It would be possible, yes, most things are. It would be a case of finding the correct definition (including what happens in the southern hemisphere), then working out an algorithm for working it out, and finally implementing the code. I guess it would be something like the pressure and temperature trend calculations (storing all of the readings for the last N hours and comparing the current value with the value N hours ago), but of course wind direction is more complicated because it's 'circular'.

[Buford T. Justice]

It appears the terms are the same for the SH according to BOM:

http://www.bom.gov.au/aviation/data/edu ... ossary.pdf