Eight Cities About to Get Hit Hardest With Days of Rain

Multiple atmospheric rivers have hit California this winter and another is on the way, with forecasts showing the storm will hit coastal cities the hardest in the Golden State.

The moisture-laden storm is expected to batter the state beginning Wednesday. It follows two atmospheric rivers that hit California earlier this month. Several cities along the state's coast are showing the biggest potential for heavy rainfall over several days.

Bob Oravec, the National Weather Service (NWS) Weather Prediction Center's lead forecaster, told Newsweek that cities in northwest California, like Eureka, could get the worst of it before the storm begins to move down the coast. San Francisco, Sacramento, San Jose and Oakland will see heavy rain on Wednesday. Rainfall will then pose a threat to Santa Barbara, Los Angeles and San Diego beginning on Thursday.

Oravec said the storm is moving quickly.

"Some atmospheric rivers are really heavy because they're slow-moving, but this one shouldn't be super heavy," he said. However, he added that a storm producing 1 to 2 inches of rain can bring flooding and mudslides, especially in Southern California.

Atmospheric rivers are defined as a "long, narrow region in the atmosphere—like rivers in the sky—that transport most of the water vapor outside of the tropics," according to the National Oceanic and Atmospheric Administration. More than a dozen atmospheric rivers battered the state last year, largely eliminating drought but creating severe problems such as flooding and mudslides.

Over the weekend, the NWS office in San Diego published a chart that showed which regions of the state would likely receive the most rain from the storm, although forecasts are still uncertain, given that the rain is days away.

"We know what you really want to know, so here it is: a look at the potential rainfall amounts for the next storm," NWS San Diego posted on X (formerly Twitter) on Sunday night. "While there is a lot of uncertainty in exact amounts, there is a solid 70-85% chance of at LEAST 1 inch for the coastal areas, valleys, and mountains Thu-Sun."

The chart showed there is a 10 percent chance of 4 inches of rain or more in the mountain regions. Following the mountains, the coasts and valleys showed the biggest potential for rain, with forecasts suggesting a 2 percent chance of 3 inches or more.

One social media user responded to the post and expressed worries about potential flooding, but NWS San Diego said flooding is hard to predict days ahead of the storm, It added that the flooding risk "largely" depends on "how much rain falls in what span of time."

The incoming precipitation follows devastating flooding that occurred in San Diego last week, in which the typically dry city saw more than 2 inches of rainfall in six hours. Destruction was so severe that Governor Gavin Newsom declared a state of emergency for San Diego and Ventura counties.