beaufort scale

noun (no longer in technical use)

1. a scale of wind forces, described by name and range of velocity, and classified as from force 0 to force 12, or, sometimes, to force 17.
2. a scale of the states of sea created by winds of these various forces up to and including force 10.

noun

1. meteorol an international scale of wind velocities ranging for practical purposes from 0 (calm) to 12 (hurricane force). In the US an extension of the scale, from 13 to 17 for winds over 64 knots, is used

to measure wind velocity, developed 1806 by Francis Beaufort (1774-1857), surveyor and hydrologist.

1. A scale for classifying the force of the wind, ranging from 0 (calm) to 12 (hurricane). A wind classified as 0 has a velocity of less than 1.6 km (1 mi) per hour; a wind classified as 12 has a velocity of over 119 km (74 mi) per hour. Other categories include light air, five levels of breeze, four levels of gale, and storm. The scale was devised in 1805 as a means of describing the effect of different wind velocities on ships at sea. It is named after an admiral in the British navy, Sir Francis Beaufort (1774-1857).