Quotes from 767-300ER:
(1)
"Airbus aircraft (A318, 319, 320, 321, 330, 340) display a wind vector on the ND when groundspeed > 100 Kts. And it doesn't just display it as a head or tailwind, it will show a direction as well as a speed."
Yes, and - as
wiggy has explained - once you get airborne it'll give you an accurate wind direction and speed. Prior to that, forget it!
(2)
"The original poster was asking how it does this.
It's a great question."
I'd say it was a very fair question, perhaps with a hint of sceptical surprise?
(3)
"Sounds like your professional piloting is quite limited.
"
Love it!
Now, if you are convinced the displayed wind direction is accurate before the a/c becomes airborne, can you answer the OP's question?