The ND shows the wind component you are flying through as a component of the flightpath based on several factors. The ATC winds may not have anything to do with the windshear, nor the actual level. Nothing, not even the aircraft, shows the vertical wind component.
If this was so easy, why are there so many go arounds and FOQA busts?
What does the ND say when you are on the ground, ready to depart?
Flight deck displays of ‘instant’ wind velocity based upon on board computations are now quite accurate when instant variation is not required. This is especially true when the aircraft is away from the ground, but their usefulness for assisting the execution of a safe touchdown, landing roll or take off roll is often very limited, both for practical and computational reasons. Updating of on-board readouts of wind velocity depends on the system which generates them. FMS wind is the most accurate, because it is based upon changes of GPS or DME/DME position, but it may only be re-calculated every 30 seconds. Wind Velocity based upon an INS is often calculated as many as 10 times per second but the result is less precise. The net effect is that neither have real value near or on the ground.
Last edited by underfire; 1st Sep 2016 at 00:59.