I never found a weather balloon, but I saw two go down. One in N. Louisiana, probably 45 years ago. It was a long way off, but you could see the parachute, plain as day.
The second one was in Tx. about 30 yrs ago. I was working on a rig in the Madisonville, Tx. area and several of us saw the parachute. It didnt appear that far away, but we were working and couldnt go investigate.
Found a lot of balloons in the woods, birthday and homecoming balloons the most.