By electrostatically charging (chemtrail spraying) the air to the capacity required for SkyNet (the medium that the military's global battle command utilizes - the OTH layer), weather modification happens but me thinks that the overall communications security concerns for the defense establishment are primary here, meaning that over-the-horizon (OTH) radar, SkyNet (a prerequisite for pulling off the remotely-controlled Operation Two Towers), enhancing signal strength in some areas (in conjunction with ops) while stifling it in others, electrostatic pulse bombs (the air BECOMES a medium that is volatile) designed to take out your local server are the deciding factors as to what types of climate engineering will happen on a given day. I am sure all of this is ALSO a convenient screen for the testing of biologicals and pharmaceuticals.
Much more here:
http://www.angelfire.com/mi/smilinks/electrostatics.html *