Drift, due to northerly winds, is evident as time progresses. (Which is why the first visible portion of the contrail does not line up with the flight path, it has already been pushed south) Drift, due to northerly winds, is evident as time progresses. (Which is why the first visible portion of the contrail does not line up with the flight path, it has already been pushed south)Those clouds are moving at about 25-30 mph, (visual estimate) yet the contrail stay lined up perfect with a plane flying at 500-600 mph in the animated gif on contrailscience. Yeah. Sure.