Gales around the coast of the British Isles are a fairly common occurrence, but inland they occur much less frequently. In the media the word ‘gale’ seems to be bandied about with little thought of what it actually means. According to the fourth edition of the Meteorological glossary, published in 1963, a gale was a 10 minute sustained mean wind speed of 34 knots (39 mph) or more. As an observer from 1970 to 1995 that’s what I always thought the definition was, but in the sixth edition of the glossary, published some thirty years later, I notice that the definition has been updated to include gusts of 43-51 knots (49-58 mph) as well. So a gale can occur without a mean of 34 knots or more if a gust reaches Beaufort force nine or higher, which to me confuses the whole issue. The definition of a gale day remains the same.
I notice the definition in the Marine Forecast glossary on the Met OfficeUKMO The Meteorological Office is the United Kingdom's national weather service. It is an executive agency and trading fund of the Department for Business, Energy and Industrial Strategy website rather ambiguously fails to mention at all sustained mean speed of 10 minutes in its definition of various gale warnings.
