Tornado Alley (PROG)

[DesertDrifter]

Cloud seeding with silver iodide to enhance rainfall is practiced in a number of states. The iodide performs as condensation nuclei to gather up water particles into raindrops or snow until they get heavy enough to fall as precipitation. It is most commonly done lower in elevation in water bearing clouds; cirrus, as you mentioned, are ice crystals at much higher elevation.

Chemtrails at the scale mentioned with some other purpose in mind would be a secret that thousands would have to be in on.