Wind Speed and Wind Gust for Weather Safety During Construction and Operations

Either a 2-minute average speed (wind speed) or an instantaneous speed (wind gust)

The National Weather Service (NWS, www.weather.gov) defines the term “wind speed” as the rate at which air is moving horizontally past a given point, such as a weather station, sensor suite, or data logger. Wind speed is either a 2-minute average speed (reported as wind speed) or an instantaneous speed (reported as a peak wind speed, wind gust, or squall).

Further, the NWS defines the term “wind gust” as rapid fluctuations in wind speed. Gusts are reported when the peak wind speed reaches at least 16 knots (about 18 mph) and the variation in wind speed between the peaks and lulls is at least 9 knots (about 10 mph). The speed of the gust is the maximum instantaneous wind speed. The duration of a gust is generally less than 20 seconds.

Both wind speed and wind gust can impact life safety, construction activities, and equipment operations on the job site and immediate vicinity. For example, OSHA prohibits work on or from scaffolds during storms or high winds without a determination from a “competent person.” OSHA Safety and Health Regulations for Construction, 1926 Subpart L Scaffolds, 1926.451 General requirements, 1926.451(f)(12) states:

“Work on or from scaffolds is prohibited during storms or high winds unless a competent person has determined that it is safe for employees to be on the scaffold and those employees are protected by a personal fall arrest system or wind screens. Wind screens shall not be used unless the scaffold is secured against the anticipated wind forces imposed.”

(Source: “1926.451(f)(12).” Edited by Occupational Safety & Health Administration, 1926.451 – General Requirements., Occupational Safety & Health Administration, www.osha.gov/laws-regs/regulations/standardnumber/1926/1926.451.)

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