No, snowy isn't white. A genetically white bird has two recessive white genes (c/c) which either inhibit pigments (pheomelanin & eumelanin) from getting into the feather, or, inhibit pigment production, so you end up with a bird that has no colour ie white (no pigments so no pattern/colour). That doesn't mean that a white can't also carry the same genes as a snowy though, for eg, a snowy would be md/md, li^h/li^h (or M+/M+, li^h/li^h, depending on school of thought)) while a white "could be" md/md, li^h/li^h, c/c!
Snowies don't have recessive white (@ least not homozygous, although it is possible for hetero white to be hiding in some birds depending on how they have been made?). I think most of the snowies in your part of the world are harlequin phased duskies, although some sources do suggest harlequin phased wild-type mallards? The recessive harlequin gene (homozygous) restricts much pigmentation (variable) resulting in birds with a lot of white, but pigment/pattern does remain.
I am not familiar with them, but do understand the genetics behind both. Some one else (CityChicker) may come along & help further who knows far more.
Edited as I just noticed "your part of the world" is like mine, so please disregard it. Do we have Snowies here? They aren't in the current standard from what I can see? Our m^d/m^d, li^h/li^h have the hobby name "silvers" or "harlequin" I thought? Maybe something in the calls?
Cheers