I have an app on my phone, Stellarium, that shows real-time positions of various satellites. I don’t know about weather balloons. The first time I saw the ISS, I didn’t know what it was, so it surprised me a little. They say it’s a full magnitude brighter than Venus, which it looked, before disappearing in Earth’s shadow.
I think some colleges, or universities may do some of them.
Maybe NOAA…