OK, let's have a look.
A human sized (+0) target wandering in the air at move 2 (+0) he'll notice latest at a distance of 1 mile (-2), but probably much earlier (75% chance at 100 miles). The same person wandering at ground level he'll probably not pick out until he can see him. Reasoning behind it: the obstacles on the ground level disturb the currents enough to make vibration sense rather useless. The more obstacles, the more disturbtions and also the less visibility.
Hagrid on his flying motorcycle (which does produce vibrations by itself) at 60mph lateral speed will be sensable with a +9 modifier (+1 for size, +1 for the engine, +7 for speed) and thus the above distances improve to 30,000 miles/16 lightseconds. Isn't long range nifty? ^^
A band of bikers driving directly towards you on the ground will be sensable probably at 10 times visibility range (+2 for size and engine, basically they count like Hagrid, but +0 for relative lateral speed). Again everything depends on obstacles.
Anything that comes directly towards you, will have a +0 relative speed (compare shooting at targets). Away from that, you have a good chance to detect most things that can be a danger to you early. Small, fast things heading right for you might slip your sense, but everything else... The most important question though is: how much obstacles and "background noise" is there. As a rule of thumb I'll apply the current winds beaufort degree as a disturbtion modifier (see Magic p.194)
This also gives you a limited kind of weather sense. You'll sense disturbances from far away storms long before they hit you.
Your biggest problem will be to distinguish between all those thousands of incoming data ... which will probably impossible. So effective distance will depend on what kind of traffic is in the air. On a virgin planet, you could probably sense most large and fast things worldwide. But please keep in mind that this info travels at the speed of sound.