Weather Tidbits: Cloud Seeding

We’ll be discussing cloud seeding in this edition of Weather Tidbits. Cloud seeding is a process that attempts to enhance precipitation from clouds. It can be a bit effective on a small scale, but not by much. First, planes use chemical flares to release silver iodide into the rain clouds. This can act as a condensation nuclei or agent for water molecules to freeze on, depending on the temperature. Silver iodide crystals are nearly identical in shape to ice crystals. Water droplets ‘supercooled’ to less than 32 degrees freeze on to the silver iodide. The resulting ice crystals begin to stick together and fall as snow. As the water from the snow refreezes, it releases heat which tends to rise. The updrafts lift moist air into the cloud and can result in even more snow. This can increase snowpack.