Forecasters said a final round of rain, snow and high winds were targeting the Pacific Northwest and Northern California regions on Friday.

The first storm was forecast to linger into the weekend and produce an additional 6-12 inches of rainfall, the weather service said. An atmospheric river prompted a high-risk warning for excessive rainfall along the Northern California coast.

"The average atmospheric river carries an amount of water vapor roughly equivalent to the average flow of water at the mouth of the Mississippi," NOAA states.