Jet Streams are a factor but their position varies. The appearance as a northbound curve is the effect of the straight Orthodrome/Great Circle line projected i

Jet Streams are a factor but their position varies. The appearance as a northbound curve is the effect of the straight Orthodrome/Great Circle line projected into Mercator. http://en.wikipedia.org/wiki/Transatlantic_flight#Transatlantic_routes http://en.wikipedia.org/wiki/Transatlantic_flight#Transatlan... [edit] I think it's fair to assume the winds are relatively stable and more intense further north so eastbound (US > Europe) flights might deviate even further to the north. http://en.wikipedia.org/wiki/North_Atlantic_Tracks#Route_Planning http://en.wikipedia.org/wiki/North_Atlantic_Tracks#Route_Pla... http://earth.nullschool.net/#current/wind/isobaric/10hPa/overlay=temp/orthographic=-5.76,48.35,605 http://earth.nullschool.net/#current/wind/isobaric/10hPa/ove...