Once the chemicals are injected, the air temperature must reach 20 degrees Fahrenheit—then water vapor begins to freeze around the silver iodide, getting big enough to fall to the ground as rain or snow.
A single-engine aircraft flies over Texas, injecting cloud-seeding particles of silver iodide into clouds from a row of flares.
Video: Jonathan Jennings; Ilana Panich-Linsman for The Wall Street Journal
Persons:
Jonathan Jennings, Ilana Panich
Organizations:
Wall Street
Locations:
Texas