strong wind event characterized by a sudden onset, a duration of the order of minutes and a rather sudden decrease in speed
NOTE 1 A squall is often accompanied by a change in wind direction, a drop in air temperature and by heavy precipitation.
NOTE 2 To be classed as a squall the wind speed would typically be greater than about 8 m/s and last for longer than 2 min (thereby distinguishing it from a gust).
Source: API RP 2MET, Derivation of Metocean Design and Operating Conditions, First Edition, November 2014. Global Standards