The parent low to the north is from the original energy, but the NAO block, 50/50 low forces the energy to transfer to the south. The GFS does it late in the game for us, so you see the closed H5 low still waaaay north, as the surface tries to get going south of NE.....if you loop the run, they will eventually stack out near the maratimes. We want that to happens faster to the south of LI.