Vector Wind Speed

The vector wind direction and vector speed are the result of vector addition. For example, if the wind is blowing from the south at 5 mph for 30 minutes and then from the north at 5 mph for the next 30 minutes, the vector speed is zero and the vector direction is undefined. Another way of thinking of it is this: imagine that a balloon floating at 30 feet above the ground moves with the wind for 60 minutes. As it meanders around it eventually arrives at a point (after 60 minutes) which is at a compass heading of lets say 90 degrees from the start point and 10 miles from its start point. The vector or resultant wind speed would be 10 mph and the vector or resultant wind direction would be from 270 degrees.