A day with lots of weather modification chemtrail flights aloft. Remember that it is not the trails that do the weather modification. But that they are markers for boundary's where the weather modification IS occurring. Some trails are 'lit-up' where there has been an ionization hit from the HAARP system. Other trails are used to find areas of drift, lift, divergence, confluence, essentially they can act like a drop of dye floating in the water.
They help in making the invisible EM energies visible.
Untitled from Scott Stevens on Vimeo.