How dangerous is that light? I know welding arcs contain a lot of dangerous UV light for example. It should be fine indirectly (clouds would let the UV pass or absorb it), but directly being exposed to it seems dangerous.
At close proximity, the huge amount of heat that can be produced by a high-current arc as well as the blast wave (known as arc blast) is much more dangerous, and can be fatal. It is a serious hazard for utility and electrical workers.
And about radio interference. This is 60 Hz, so I doubt that's an issue.