Re: Does the wind have velocity?

"Wind", that are billions of air molecules moving relative to the surface 
of the earth in a certain direction. Each molecule has, at a given time, a 
certain velocity. There are two different movements that have to be 
distinguished:
1.) Thermal movement. Dependent on the temperature of the air, the air 
molecules move with velocities of about 300 m/s in random directions. Some 
move faster and others more slowly ("Maxwell velocity distribution"). They 
often hit each other. This movement is the main reason for the air 
pressure.

2.) On a windy day, additionaly to this random movement there is some 
movement of the air moleculs in a certain direction. This is what we call 
"wind". The simple picture is, of course, that all the molecules move in 
the same direction at the same velocity. This is the "wind velocity". 
However, this velocity (also depending on time) depends on the place that 
you measure it. You can compare that to a river that flows faster in the 
center and more slowly at the bank. In science, people talk about "vector 
fields". On a mountain the wind might be faster than in the valley. Often, 
the differences are rather small and we simply talk about "the" wind 
velocity.