Tropical cyclone scales barometric pressure is low compared with its surroundings. Other classifications historically used include: cyclonic storm where the winds did not exceed force 10 on the Beaufort scale and a Cyclone where the winds are either force 11 and 12 on the Beaufort scale. Between 1924 and 1988, tropical cyclones were classified into four categories: depression, deep depression, cyclonic storms and severe cyclonic storms. However, a change was made during 1988 to introduce the category "severe cyclonic storm with core of hurricane winds" for tropical cyclones, with wind speeds of more than . During 1999 the categories Very Severe Cyclonic Storm
Francis Beaufort scale, decoded as 32–38 mph, or a "moderate Gale". Beaufort, like other patrons of exploration, has had his name given to many geographical places. Among these: Beaufort created the Beaufort cipher. It is a substitution cipher similar to the Vigenère cipher. Francis Beaufort Rear Admiral Sir Francis Beaufort, KCB, FRS, FRGS, FRAS, MRIA (; 27 May 1774 – 17 December 1857) was an Irish hydrographer and officer in the Royal Navy. Beaufort was the creator of the Beaufort Scale for indicating wind force. Francis Beaufort was descended from French Protestant Huguenots, who fled the French Wars of Religion in the