California could be hit with days of heavy rain

A fast-moving atmospheric river is heading toward California this week and could pack a punch, threatening periods of heavy rain and possible flooding and debris flows in recently burned areas.

- RONG-GONG LIN II AND SUMMER LIN

After arriving in Northern California on Wednesday, the storm system is expected to land in Southern California on Thursday, where it could remain all the way through Saturday. It could produce the most rain downtown Los Angeles has seen in at least a month, and possibly since February.

"There is a chance for burn area flash flooding and debris flow issues. A flood watch will be possible for burn scars," Rose Schoenfeld, a National Weather Service meteorologist in Oxnard, said Tuesday afternoon.

Although the storm brings some concerns about flooding, it could also mark the end of the autumn fire season. Rainstorms in Northern California have already lessened the seasonal fire danger there considerably, and this storm could do likewise in the Southland.

The National Weather Service office in Oxnard called the forecast storm "potentially significant," with roadwayflooding expected in spots, rockslides possible on canyon roads and a chance of mudflows.

The storm could snarl traffic in Los Angeles and Ventura counties for the Thursday afternoon and Friday commutes, causing water to pool on roadways. The L.A. metro area could be hard hit, with localized freeway flooding in low spots, forecasters warned.

In the L.A. area, there could be 1 to 2 inches of rain on the coast and in the valleys, with 2 to 4 inches possible in the mountains and foothill areas.

"We're looking at moderate to locally heavy rain rates with this system," Schoenfeld said.

Between Thursday and Friday, Long Beach could get 108 inches of rain; downtown Los Angeles, Redondo Beach, Pomona and Pasadena, about 1.3 inches; Oxnard, 1.51 inches; Santa Clarita, 1.75 inches; Westlake Village, 1.98 inches; Santa Barbara, 2.22 inches; and Ojai, 2.88 inches.

Winds also could be an issue, with peak gusts of 50 mph along the Grapevine section of the 5 Freeway and in the Antelope Valley.