Weather modification: cloud-seeding

A ground-based cloud-seeding tower at Alpine Meadows ski area near California’s Lake Tahoe. It spits out silver iodide particles that are the right size and shape to help precipitation form.

It’s Not Magic On The Mountain, It’s A Rain-Making Machine
January 09, 2014

The snowpack in the Mountain West this year is at just a small fraction of its normal level. In fact, 2013 was the driest year ever recorded in many parts of California, and there’s little relief in sight. But water managers are trying to squeeze every last raindrop out of Mother Nature with a technology developed in the state more than 50 years ago: cloud seeding.

Tilley runs the cloud-seeding program at the Desert Research Institute in Reno, Nev. Weather modification, as it’s called, is about making rain, not making clouds.

Most skiers don’t notice the green metal bunker with a chimney on top. This isn’t a snow-making machine like the ones ski resorts are relying on this winter. It’s designed to improve the water supply in the area by releasing tiny particles of silver iodide.
These are the seeds in cloud seeding, rising thousands of feet up into the air.

HSDB: Silver iodide