South Bay residents face more than an inch of rain, possible street flooding and hazardous beach conditions as a moderate storm moves across Los Angeles County on Wednesday, Oct. 21, and Thursday, Oct. 22.

The National Weather Service forecast about 1.31 inches of rain at Los Angeles International Airport, the Los Angeles Times reported. Rainfall totals across much of the county are expected to average about 1.5 inches, according to the Daily News. South-facing mountains and foothills could see 1.5 to 3 inches.

Bryan Lewis, a meteorologist at the NWS office in Los Angeles, told Yahoo News that rain totals were trending upward, with the heaviest rainfall expected from late Wednesday morning through late Thursday morning.

The NWS issued a flood watch for Malibu and the western and eastern Santa Monica Mountains, effective from 4 p.m. Wednesday through 4 p.m. Thursday, according to the Daily Breeze. The agency warned that flooding could strike poor drainage and urban areas.

"Extensive street flooding and flooding of creeks and rivers are possible," the NWS said in its advisory.

The flood watch does not specifically name the five South Bay cities. But the broader storm covers the entire county, and the NWS estimated a 20% to 30% chance of thunderstorms across Los Angeles and Ventura counties, the Los Angeles Times reported. Those storms could produce lightning, heavy downpours, small hail and isolated waterspouts, according to the NWS forecast.

Commute and coastal hazards

NWS forecaster Ciliberti told Patch that short, intense bursts of rain pose the biggest risk. She urged drivers to slow down and expect reduced visibility and slick roads, especially during the Wednesday afternoon and Thursday morning commutes.

"With these types of storms, a lot of times what gets us is shorter term, 15- to 30-minute heavy showers that can deliver a lot of rain in that period of time," Ciliberti told Patch.

Ciliberti also encouraged residents to prepare for possible localized flooding, especially in areas with drainage problems.

A beach hazards statement remains in effect for the Los Angeles County coastline until 3 a.m. Friday, Oct. 23, according to the NWS. The agency warned of dangerous rip currents, elevated surf of 3 to 6 feet on south- and southwest-facing beaches, and possible minor beach erosion. Beachgoers should swim only near occupied lifeguard towers and stay off rocks and jetties, the NWS advised.

What comes next

The storm is expected to clear the region by Friday. Dry weather and sunshine should return over the weekend, though another round of Santa Ana winds could develop with gusts of 30 to 50 mph in the mountains, according to the Daily News. Temperatures are expected to rebound into the upper 70s and 80s across coastal areas.

Residents can monitor updated flood warnings at the NWS Los Angeles office website.