I always feel inspired to write during storms. Thankfully, I have a laptop with a long-lasting battery, so I can disconnect it from the wall during lightning storms.
For a while, I had a storms CD. When I was having a spot of trouble getting inspired, I'd close the blinds and play the CD, and pretend there was a storm raging behind me. It helped. Because, I've noticed, there's always action in storms.
Often, the weather is just a background, a setting that doesn't influence the story all that much. But sometimes, active weather becomes a part of the story. Melting sun? That's active weather; it interferes with the characters' actions. Driving snow? A blizzard makes it hard to see, disrupts radio signals, and makes going outside dangerous. Pouring rain, lightning, and whipping wind? It's all fun and games until someone has to try to fight in it.
The sequel to Into the Tides has the working title Derecho right now. A derecho is a type storm system that's basically a long line of powerful, fast-moving storms with winds that blow in the direction it's going. The title may well change as the manuscript continues, but it refers to the fact that magic has played havoc with the weather, and so the weather will be a minor character in the story.
How do you use weather to strengthen your scenes? Do happy moments happen in sunny, cheerful weather? Do your storms do more than set the mood--do they play a part in how the events take place? Or is your weather a backdrop, a hint at the mood of the story without playing an active role in it?
In which books has weather been an active character? What books do you think use weather to the best effect?