Get ready for ‘hours of widespread rain’

Storm could sit off the coast, bringing ‘quite a bit of instability’ — or spin off and be a bust.

- SUMMER LIN AND RONG-GONG LIN II

A VEHICLE splashes along a flooded road last month. This week's storm will be "a long-duration event."

An atmospheric river is barreling toward Southern California this week and could bring heavy rain, and with it, arisk of flooding and debris flows in recently burned areas.

“This is a long-duration event,” Ryan Kittell, a meteorologist with the National Weather Service office in Oxnard, said Wednesday afternoon. “We expect many, many hours of widespread rain over the area.”

There will be two main peaks of the storm for the Los Angeles area — Thursday night into early Friday, and then on Saturday. Saturday is of particular concern, as there is a high degree of uncertainty in the forecast — even just days beforehand.

One concerning scenario would be the storm sitting just off the California coast, which would produce “several hours of pretty steady, moist southeast flow, with quite a bit ofinstability,” Kittell said.

Thereis “the potential for bursts of heavy rain, which would induce flash flooding and/or debris flows” on Saturday, Kittell said. There's also a remote risk of other severe weather events, including localized damaging winds and even a tornado.