Severe Weather iphone App

I like the free app WeatherTapZoom partly because of the excellent underlying map that it uses. I use it as a moving map while I drive to see a Sat view of where I'm at when the weather is good. Last summer it helped me to keep going as it showed there was a small gap between two BIG thunder storms in front of me if I hurried. Another time it showed that it would be best to stop for an hour as the storms were moving fast but if I kept going I would run into them. Stopped and had a early dinner and then it was clear sailing.
No, it will not alert you to bad weather but usually I can see or hear it coming.