Symbol for current, ongoing event

In my app I need to display an icon for an event which is currently ongoing. It's a forecast app for forecasters, where they can issue a forecast in certain time window (event). I'm currently using a plane icon from fontawesome, but I'm not sure at all if it's the best match for that, especially because my app has nothing to do with flights:

I would like something more general, but I have no idea what could symbolize an ongoing event.