Still on the whole chinese balloons are spying other countries on HN someone shared a fun “Spy Balloon Simulator”. You drop the balloon somewhere and see what trajectory it takes. The models uses actual atmospheric data from ERA5: https://spyballoonsim.hornetsnestguild.com/
Apparently NOAA (National Oceanic and Atmospheric Administration) also have a public simulator: https://www.ready.noaa.gov/hypub-bin/trajsrc.pl?trjtype=4
