There's been a Navy E-6B Mercury and an AF E-4B Nightwatch flying around over the central US. Both are Airborne Command Posts, i.e., doomsday planes.
The Nightwatch tail number is the one that took/followed Sec'y Mattis to/from Brussels. There's usually a different tail over the central US. Maybe it's shadowing POTUS.
Planefags did an outstanding job today while I was fucking off at the lake. Bakers did a great job, too, adding to notables so I could see them now that I'm home and comfy.
o7