More Atmospheric Rivers Are on the Way. Here’s What the West Can Expect.

The Western United States and Canada are likely to see excessive rain and heavy snowfall from a sequence of back-to-back atmospheric rivers beginning this weekend and continuing into next week.

An atmospheric river is like a powerful fire hose with only one person holding it. It often has a narrow path of the heaviest and strongest precipitation. It can be challenging to pinpoint where the heaviest stream of water will fall. It could be strong in the San Francisco Bay Area, and little might fall in Southern California, or vice versa.

This early in the forecast, meteorologists are certain that the weather pattern is set up for a series of atmospheric river events — in some locations likely reaching a three or a four on the Atmospheric River five-point scale developed by the SCRIPPS Institution of Oceanography at UC San Diego — along the West Coast. But they are less certain where the heaviest precipitation will fall, especially later in the week. There are at least three atmospheric rivers over the next week, and an additional one beyond that.