If you’re located around the Sea of Japan (Hello, Kanazawa), then you’ve likely been lucky enough to experience thundersnow — the exciting combination of snow, flashes of lighting, and thunder that shakes your apartment walls.
In fact, here in Nonoichi (next to Kanazawa), the past few days of snow have been filled with class-disrupting claps of thunder as the snow pummels the ground below.
So what’s up with thundersnow? Well, The Straight Dope gives a fairly readable explanation of why thundersnow occurs, but it basically comes down to the fact that lightning and thunder occurs when there’s a lot of movement, which generates electrical charges that need to be released from the clouds. This movement typically occurs when warm air is rising, and warm air usually rises when the weather is hot and there’s a lot of humidity. In other words, winter isn’t your typical situation for lightning and thunder — think of your dry, cracked lips in the winter months.
Now, I’m not a meteorologist, so bear with my attempt at understanding this… Water is often warmer than the surrounding winter air, so it could be that the “warm” water in the Sea of Japan heats up the freezing winter air (by “heat up”, I mean it makes the air slightly warmer than freezing), and that air rises — as heat does — creating the fabulous umbrella-snapping wind we’ve come to love, and ultimately creating a lot of static charge as all that air rubs up against itself, and needs to release the static electricity as lightning and thunderous booming.
And why the joyous apartment-shaking? Well, thunder does that in summer here, too, but apparently thundersnow can only be heard within 2-3 kilometers of where the lightning strikes, so maybe when we hear the thunder, we’re just hearing the stuff that’s really close to us, so it’s obviously going to be LOUD. Also, sound can apparently travel better through cold, dense air, so we may be able to hear the thunder a little more effectively in winter. But then again, I’d think that the snow would muffle the sound more or something.
Let me point out again that I’m not a meteorologist. And the only science I took in college was geology, so…
Interested in learning more about our fabulous thundersnow? ABC News wrote an interesting article that will make you feel special for living somewhere where you can reliably experience thundersnow. Wikipedia also has an article about it.