I believe that canine fear of thunderstorms is not only about noise and light.  Perhaps it's electrical. Having fostered many rescue dogs, I've become quite sensitive to recognizing expressions of anxiety.  With my own dog, I realized that she was having anxiety when there were predicted storms but neither thunder nor lightning that I could detect.  Through the internet I found live lightning tracking information.   Over the course of a year, I was able to verify repeatedly that my dog was reliably reporting lightning strikes as they happened off the coast of Santa Cruz from her observation post in the Central Valley of California.  I hear you  - I didn't believe it at first either.  For those of us who consider premedicating for predicted bad events, this is pretty hard to stay on top of this kind of sensitivity.  Denial of the importance of the events didn't work.  So once I confirmed the lightning, we worked on making distant lightning a trigger for happy times.  This seemed to work for her: we handled it almost like clicker training - lightning strick -> treat.  "Good dog, thanks for warning me about the storm.  Yes, I got it, and now you can relax."  I never could have made the associations without the timely strike reports on the internet.