Winter blanket (4)
I believe the answer is:
'winter blanket?' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for snow that I've seen before include "Winter weather" , "'The -- Queen', fairy tale" , "White specks on screen resulting from interference" , "Weather feature" , "feature of 27 [THE BIG FREEZE]" .)