Sorry, you can't control the weather and make it snow tomorrow. And sorry, you can't move your whole family to a place where it'll snow for a day. But if you really want to see a white Christmas (and that should be every non-Grinch) you can use a magical combination of diaper lining, light beer and Epsom salt to create perfect man-made versions of snow, frost and ice. The resemblance is pretty uncanny.
Household Hacker has the guide to fulfill every kid's dream of a white Christmas. For snow, simply tear up diaper lining and add water. For frost, create it by mixing light beer with Epsom salt to smear on your windows. For ice, Epsom salt and some glue should work pretty perfectly.
When you put your kids to bed tonight, why not add some snow to the window sill to make them believe they're having a white Christmas. Let dreamers dream.