a gust or flurry of rain or snow.
Origin of dwy
compare dial. (Isle of Wight) dwyes eddies, (Wiltshire, Hampshire) twy coastal squall; further relations unclear
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019
Examples from the Web for dwy
Thmilakth thwore like a twooper; but nothing could thwop the thaithe till it wolled thlap down into a dwy dith.The Mysteries of London, v. 1/4|George W. M. Reynolds