"strong, sustained snowstorm," 1859, origin obscure (perhaps somehow connected with blaze, n.1); it came into general use in the U.S. in this sense in the hard winter 1880-81. OED says it probably is "more or less onomatopœic," and adds "there is nothing to indicate a French origin." Before that it typically meant "violent blow," also "hail of gunfire" in American English from 1829, and blizz "violent rainstorm" is attested from 1770. The winter storm sense perhaps is originally a colloquial figurative use in the Upper Midwest of the U.S.