Express Way Where's My Umbrella? What’s your favorite tune about rain? Is it “Raindrops Keep Fallin’ on My Head,” by B.J. Thomas? Or “Rainy Days and Mondays,” by Karen Carpenter? Maybe “I’m No Stranger to the Rain,” by Keith Whitley? Or “Blue Eyes Crying in the Rain,” by Willie Nelson? I know, it’s a tough call. Now, let me pick your brain. With all the hit songs recorded over the years about rain, why would we want to keep it off us? After all, rain’s a blessing. It purifies the air. It...