Heavy rain from a persistent atmospheric river pattern continues to impact California this week. Here's what's causing it.

The National Weather Service extended a Flash Flood Warning for parts of Los Angeles and Ventura counties, effective until 6 p.m. Wednesday.

The Bay Area and Central Coast are facing multiple rounds of powerful, atmospheric river-fed winter storms this week, bringing heavy rain and damaging winds.

Rain totals will range from about 2 to 4 inches over the 3-day stretch from Wednesday to Friday with the heaviest accumulations in North County.

Knott’s Berry Farm and Six Flags Magic Mountain will close on Christmas Eve due to heavy rain as a powerful “atmospheric river” storm system moves through Southern California. Knott’s and Magic Mountain will be closed on Wednesday, Dec. 24 due to inclement weather, according to each park’s official website.

A series of powerful Pacific storms will pound the Bay Area and Central Coast through Christmas week, bringing periods of heavy rain, damaging winds, flooding and dangerous surf, forecasters said Monday.

Flooding forced the closure of a portion of state Highway 24 in Orinda early Thursday morning as heavy rain continued to soak the Bay Area.

The National Weather Service says snow and high winds are expected, while heavy rain could pose possibly 'life-threatening' risks in parts of the region.