Beaufort scale Meteorol.
(ˈbəʊfət)
[Devised by Admiral Sir Francis Beaufort (1774–1857).]
A series of numbers from 0 to 12 assigned by Captain (later Admiral Sir Francis) Beaufort to indicate the strength of the wind from a calm, force 0, to a hurricane, force 12.
The Beaufort numbers and their limits of velocity have varied in different countries since the scale was devised c 1805. The specification of the Beaufort scale adopted now by the Meteorological Office allows for 17 Beaufort numbers ranging in velocity from 0–0·2 metres per second (0) to 56·1–61·2 metres per second (17).
| 1858 [see storm n. 1 b]. 1906 Beaufort Scale of Wind-Force (Rep. Meteorol. Office) 5 Assume first that the velocity of motion of the air is the ultimate measurement to which the numbers of the Beaufort scale shall be referred. 1933 Jane's Fighting Ships 22 Trials..151,000 S.H.P. = 32·07 kts. (run in bad weather, wind force 6 Beaufort scale). 1961 Times 5 Aug. 3/1 South-westerly winds between force 5 and force 6 on the Beaufort scale meant rigorous yachting conditions. |