Weatherwise, snow isn't something we give much thought to this time of year. But some day this week, it's very likely that snowflakes will be flying within five or ten miles of your backyard.

Now this isn't meant to be some bad weather joke. Instead, it's kind of a backhanded way of recognizing that the atmosphere is three-dimensional, and just a few miles up, weather conditions are very different. For example, in the belly of a summer thunderstorm, 20 or 30 thousand feet up, the temperature is actually below zero, and snowflakes are flying. But as those flakes fall, they pass through much warmer air, and melt, leaving raindrops to splatter on the ground. Six months from now, the warmer air will be gone, and the snowflakes will have a fighting chance to make it all the way down.

But just about any time of the year around here, snow's really not that far away, if you're willing to think 3D.