As more rain falls, the risk for dangerous flash flooding, debris flows and landslides will increase as the ground becomes too saturated to hold and streams and rivers continue to rise and overflow.
What can make atmospheric rivers difficult to forecast is that they are narrow bands of moisture, and they hold dramatically less moisture around their edges than they do in the center.
So a specific location could see a huge variety in the potential forecast in the days and even hours leading up to an event.
For this storm, that means a place south of the Golden Gate Bridge, like San Francisco, could end up seeing only an inch of rainfall or more than six inches by Friday.
Here’s a look at what’s happened so far, what the region may face next and why it’s so hard to be sure.
Persons:
it’s
Locations:
Northern California, West Coast, San Francisco