As I write, North West Europe is between storms Austen and Boelo, and listeners to weather forecasts are constantly regaled with threats of wind speeds up to seventy or eighty miles per hour. But frankly, I have little idea what that truly signifies. I fell to thinking. Back in the 1960s the BBC Weather Centre decided to follow the Met. Office practice and make the change to SI, since when our thermometers are graduated in °C, our visibility is expressed in metres, our rain falls by the millimetre and our snow by the centimetre. Why, then, do we cling on to m.p.h. for wind speeds?
Continue reading “Measuring wind speed”
