Jet Stream, anons.
Airspeed is affected by winds aloft. Strong tailwinds increase speed over the ground and headwinds do the opposite.
Yes it is. A jet aircraft flying 600+ kt airspeed over the ground is being pushed by winds aloft.
Flight tracking software shows groundspeed.
Winds aloft show 100+ knots at that location/altitude. Max airspeed of a GV is less than 600 knots. He is Likely at a normal cruise speed with a lot of wind behind him which increases the groundspeed shown.
150-170 kts