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
Full-Scale Wind Tunnel Full-Scale Wind Tunnel The Full-Scale Tunnel (abbreviated FST, also known as the 30-by 60-Foot Tunnel) was a wind tunnel at NASA's Langley Research Center. It was a National Historic Landmark. In 1929, National Advisory Committee for Aeronautics began construction of the world's first full-scale wind tunnel. The design team was led by Smith J. DeFrance. The tunnel was completed in 1931 (dedicated 27 May) at a cost just under $900,000. It was a double-return tunnel capable of moving air at speeds up to 118 miles/hour (190 km/h) through its circuit. It had a 30 ft by 60 ft (9.1 m