Thunderstorm

I've been watching the thunderstorm from my patio. There hasn't been much wind so I could stand right at the corner of my patio roof and watch the rain and lightning and listen to the thunder. Sometimes the trees in my backyard were perfect black silhouettes and sometimes they were lit up green like on a clear sunny day. At one point I saw a flock of about 15 birds heading down fast, probably between Woodmere and Sherbourne. What were they? If I had to guess I'd say it was a group of migrating Common Nighthawks but I really don't know. What a storm!