Sort:  

Geeze, you're not kidding. That is a load of planes... though according to this, none in our area, just as the sky is telling me. It will be very interesting to see what the map says next time the sky is covered in lines.

also check the barometric pressure and temperature to see if that is a factor. Some of the variation could be to other whether events, like if there is a big storm on the east coast of the US I would expect to see fewer flights going west from France.