Rain is expected to arrive in the Bay Area on Thursday. Once it starts, the region won't see dry weather for at least a week, according to the latest forecast from the National Weather Service. "There is certainty that it is going to rain for the next seven days and likely into the Christmas holiday and beyond,

While flooding may not reach the historic levels seen last week, a KIRO 7 meteorologist said the overall impacts could actually be worse.

A map from the National Weather Service in Portland shows where the most rain is likely to fall. In Oregon, the central Willamette Valley and the coast have the greatest chance of two inches of rain or more between Thursday and Friday. Corvallis and Coos Bay have a 90% and 94% chance, respectively, of hitting two or more inches in about 24 hours.

Parts of California are bracing for a series of rain and wind events over the next week as back-to-back atmospheric rivers move through the state.

An atmospheric river will bring periods of rain and snow. While impacts continue, this system is not expected to be as strong as yesterdays front. Find out the details here.

Preparations are underway for potential flooding in Estacada. At least one resident says she has never seen the water so high in the Clackamas River.

Cowlitz River below Mayfield Dam also remains under flood warnings on Tuesday, “until further notice,” as the river flow has risen above 25,000 cfs—the flood stage threshold. Flooding is expected from Mayfield Dam downstream through Toledo, covering farmlands and roads, mainly near Toledo, as flows stay near 29,000 cfs through Wednesday.

The weather service has issued a flood watch for northwest Oregon and southwest Washington from early Thursday to early Saturday.

(THE CONVERSATION) Along the U.S. West Coast, atmospheric rivers are dreaded for the damage they can cause, but they are also essential to the region’s snowpack and water supply, as Qian Cao, a hydrologist at the University of California, San Diego, explains.