Green’s Dictionary of Slang

snow n.2

[abbr. snow job n.1 ]

(orig. US) smooth talk, bluff, bluster, lies.

[US]W.A. Heflin US Air Force Dict.
[US]E. Gilbert Vice Trap 128: We’ve all been brainwashed by the snow he’s been shovelling.
[US]‘Iceberg Slim’ Pimp 31: I put the snow machine into high gear.
[US]G.V. Higgins Friends of Eddie Coyle (1973) 13: ‘Think we’ll have snow by then?’ ‘I think we’re gettting some right now.’.