sustained wind speed

The wind speed averaged during a certain period of time. The standard averaging periods are 2 minutes (as defined by the United States National Weather Service) or 10 minutes (as defined by the World Meteorological Organization). A special case is the 1-min average for tropical cyclones as reported by the United States National Weather Service and the Joint Typhoon Warning Center.

The term maximum sustained wind speed, when applied to a particular weather system (e.g. a tropical cyclone), is the highest average wind speed measured at an unobstructed point and time at 10-m altitude during either a 1-min time span (as defined by the United States National Weather Service and the Joint Typhoon Warning Center) or a 10-min time span (as defined by the World Meteorological Organization).

NOAA, 2021: National Weather Service Instruction 10-0604: Tropical Cyclone Names and Definitions. Analyze, Forecast and Support Office. 13 pp. [Available online at https://www.nws.noaa.gov/directives/sym/pd01006004curr.pdf.]

Term edited 2 February 2022.

Any function of time f(t) is periodic with period t if f(t) = f(t + τ) for all times t, where τ is the smallest number for which this equality holds.