Have you ever flown a transatlantic flight (non-stop) above 35,000 ft with real weather?

 

I am making a Madrid - New York flight with cruise altitude at 39,000 ft with real weather provided by Active Sky 6.5. Strong wind speeds above 90 MAG and strong wind speed changes lead me to overspeed and now I am at Gander, the speed dropped from 0.84 match to 0.73 match I had to request FL380 from FL390 and engines at full power. Oh my God! this is really difficult, what a hell! I want to see land and everything turn ok again.

Yes

I have done many London-NY flights at between FL53-60 !  In the sim I hasten to add.

 

Your best bet is to use a registered version of FSUIPC and the weather smoothing options should help.