Watching the line of storms come through (with the resultant impact on
aviation traffic) this PM, I noticed the round ball with the flight track
at SR71-altitudes and there went the last of my facade of productivity for the afternoon.
It seems to be dragging at a low altitude tracking the tail of the storm.
https://www.flightradar24.com/blog/keep-your-eye-on-the-hbal-tracking-project-loon-balloons/
https://loon.com/