Atmospheric rivers can cause catastrophic flooding and landslides but are crucial for water supply. In an era of increasing whiplash between flood and drought, can we learn to embrace the rains?

The storm that hit Abbotsford is known as an atmospheric river. These systems are common along the west coast of North America and midlatitudes around the world. They account for one-third to one-half of the annual precipitation in some areas and represent a major source of fresh water for many countries. But studies suggest that atmospheric rivers are becoming more volatile and are delivering water in bigger bursts. Paradoxically, recent storms, including the one in British Columbia, have occurred between some of the hottest and driest summers on record. When they deliver needed rain, it’s too much for parched soils and concrete channels to contain. This pendulum swing between deluge and drought—what meteorologists have started calling “weather whiplash”—will only grow more pronounced as the planet warms.