White squall

Squall Squall (skw[add]l), n. [Cf. Sw. sqval an impetuous running of water, sqvalregn a violent shower of rain, sqvala to stream, to gush.] A sudden and violent gust of wind often attended with rain or snow. [1913 Webster]

The gray skirts of a lifting squall. --Tennyson. [1913 Webster]

{Black squall}, a squall attended with dark, heavy clouds.

{Thick squall}, a black squall accompanied by rain, hail, sleet, or snow. --Totten.

{White squall}, a squall which comes unexpectedly, without being marked in its approach by the clouds. --Totten. [1913 Webster]