Snow, snow, snow

Earlier this morning, I dreamed that it was snowing. These were giant flakes, perhaps a foot across. I saw them through our living-room window, which looked onto a city sidewalk that had already been shoveled. The crews are out early, I thought. Analyst, do your worst.

[Illustration by Harry McNaught, from Weather: A Guide to Phenomena and Forecasts, a Golden Science Book (1965).]