"sudden, violent gust of wind," 1719, originally nautical, probably from a Scand. source (cf. Norw. skval "sudden rush of water," Sw. skvala "to gush, pour down"), probably ult. a derivative of squall (v.).
"cry out loudly," 1631, probably from O.N. skvala "to cry out," of imitative origin (cf. squeal).
squall (skwôl) Pronunciation Key
A brief, sudden, violent windstorm, often accompanied by rain or snow. A squall is said to occur if a wind having a sustained speed of 40 km (25 mi) per hour lasts at least 1 minute and then decreases rapidly. See also squall line.