Amid perpetual drought, population growth, and trillions of gallons of water used in desert agriculture, much of America’s West is in desperate need of more rain and snow. A team of engineers at a Southern California tech company say they believe drones could be part of a solution. The team at Rainmaker says drones are the most precise and cost-effective way of cloud seeding, a process that uses molecules of silver iodide to attract water droplets and enhance the amount rain and snow that falls. To produce more rain than would occur naturally, Rainmaker sends a drone into a cloud that is not yet producing rain or snow and releases silver iodide — an ice nucleating molecule — from the drone.