Ref: Treadgraph 21st Nov 2020, 21:23 post FedEx 777F speed East - Jetstream :
I love this sort of stuff, looking at the weather archive from that day / time , within a couple of hours.
FedEx was enjoying a tailwind of around 200 kts + ( green colour ) the Jetstream ,
while TAS had to battle this @ altitude. Stay Safe all ... TFC.
Jetstream position , near the time of Treadgraphs original , interesting post.