On the weekend, the effort usually shifts to outlying Houston suburban areas. When you see a plane putting out short bursts of aerosol, he is making the initial pass to create a pattern that will look like individual clouds. They are not turning off the pumps until after they begin their turn away from the pattern. In semi-rural areas like this one, it is usually possible to point to a heavy concentration in one direction or another and name the town that is under it. It is absurdly easy to tell the difference between real clouds and spray concentrations, but only if you've spent a little time watching them being built.
Real clouds have tops and bottoms.
Spray patterns just spread out into thin layer. A person looking up for the first time will almost never notice the strangeness unless someone points it out - and even then they may not believe that what they are seeing is man made. The general pattern has been Saturday and Sunday over outlying areas of Houston, particularly the west, ending with a heavy pattern over the I-45 corridor carrying bumper to bumper traffic returning to the city after a weekend away. Then Monday off, except for a few weeks after the July 4th holiday when they took Thursdays off, and then four days hitting populations in an arc that covers a zone extending from 30 out to 70 miles from the city center. Reports I've received from other areas around the country suggest similar tactics around a number of large cities.