Oh! I have slipped the surly bonds of Earth. And danced the skies on laughter-silvered wings.
John Gillespie Magee, as you may have gleaned, was fond of aircraft:
Up, up the long, delirious, burning blue,
I've topped the wind-swept heights with easy grace
Where never lark nor ever eagle flew.
Wise lark! Wise eagle! Windswept heights they are indeed, where steady gales may blow at well over 100 m.p.h. It is a matter of common experience that the wind seems stronger when you are high up. It is usually windier, for example, at the summit of a hill than in the valley below. Here, of course, the difference can sometimes be explained by the shelter available in the valley, but the principle, in general, is true: wind usually increases with height.
But it is more complex than that. Above the turbulent layer in the first few thousand feet above the ground, there is a tendency for what meteorologists call the "westerly component" of the wind to increase with altitude. This means that if there are winds blowing from the west at the Earth's surface, this westerly wind will become stronger and stronger the higher you go in the atmosphere.
But if the surface wind is from the east, , this easterly wind decreases with height. With increasing altitude a zone of relative calm will usually be encountered, and higher still a westerly develops, becoming stronger with increasing height. Surface easterly winds are therefore often confined to a shallow layer quite near the ground, whereas westerly winds are deep.
The end result in either case is a tendency for winds in the high atmosphere to blow from west to east, and to become stronger with increasing height, but this increase in speed does not go on indefinitely.
You will recall that temperature normally decreases with height up to a level called the tropopause some 35,000 feet above the ground, and then remains constant or even increases with altitude. Wind speed also experiences a discontinuity at the tropopause: typically the westerly wind increases in strength with increasing height up to the tropopause, and then its speed drops again as you go higher still.
The strongest winds in the atmosphere, therefore, are normally to be found blowing from a generally westerly direction some 35,000 feet above the ground, which happens to be close to the cruising altitude of jet aircraft. The typical speed of the winds is perhaps 40 or 50 m.p.h.; 70 to 80 m.p.h. is not at all uncommon; and winds of 150 m.p.h. or even higher are encountered by these aircraft every now and then.