Special Delivery (a piece of animation for adults, not children) will know why you have to keep things clear for the mail carrier.
Anyway--if you're looking for snow books and your kids are a bit past The Snowy Day but maybe not ready for The Long Winter, here's a book that our Squirrelings enjoyed at that age: Oliver and Amanda and the Big Snow. How could we not identify with a snow book that starts out with "Digging Out?" (The Oliver and Amanda books are structured like Frog and Toad, with four or five short stories in each one.)
And if you're really an expert on snow stories, you can always go back to our Carnival of Homeschooling: Snowed-In Edition, and see if you can identify the bits of books there. (Answers here.)