Are Double Rainbows lucky?

I just had to share this with you because it seems like such a rare thing. Sunday night as we were heading north on Lake Shore Drive, we witnessed a double rainbow east over the lake. We had been at Navy Pier and there was a downpour and some hail. But as might be expected with our freakish weather, the sun came out shortly after and we had some sun showers. I know to always look for rainbows when it is sunny after a rain; and just as I was telling our boys to look for rainbows, there was a rainbow. No wait! Not one but two, a really brilliant one and just above it a more faint one. Here's some pictures taken as we were clipping along the Drive.

Speaking of Double rainbows. Check out the shot here. It is much better than mine, but you need to scroll down to see it.