1. Wind speed is measured in m/s or given in terms of the Beaufort scale. A storm is defined as upwards of 20.8 m/s or windspeed 9 on the Beaufort scale.
2. The wind speed is the velocity of the air against the ground. It is a directed size, defined as a vector with a horizontal and a vertical component.
wind velocity, velocity of wind
https://www.pik-potsdam.de/services/climate-weather-potsdam/climate-diagrams/wind (1.); https://en.wikipedia.org/wiki/Wind_speed (2.)
Author: Frithjof Kühnert