North American hams/SWLers are now in the "window of possible copy" regarding the amazing balloon launched 66 days ago by David VE3KCL.
If all goes well the balloon will complete its 5th circumnavigation of the planet within the next two days. As I write (30 April, 2130Z) the balloon is a few hundred miles west of California and heading east at 52 knots. It only transmits during daylight hours and has about 6 more hours of daylight today.
It is transmitting on 30m WSPR with a power of 10 milliwatts. Today and tomorrow should present opportunities for copy in NA. It is already being copied by W6/W7 WSPR receiving stations.
I currently have my RSPDuo, 100-foot high dipole and WSJT-X listening for it and will leave the setup running overnight, or at least until sunset at the balloon's current location, which will be about 0300Z.