First up is a concept by a creative author ironically named Lisa Storms. I'm in love with her pompom and raindrops ceiling decor!
Here's another version of pompoms and raindrops, but now with white and blue balloons to liven things up more. Visit My House of Giggles to see the rest of the party and the cute celebrant.
How about a more colorful take on the theme? Look at how Crossing the Bugger-Dixon Line adds "bow" to the word "rain":
And what's rain without umbrellas, right?
Finally, how about showering some loot on the guests? See these awesome pinata and giveaway:
Source? See the rest of those kids have fun at the party by A. Party Style.
Hope this entry took away your gray clouds!