It’s Storm No. 2 -- Slow, Strong, Possibly Perilous

Authorities still cleaning up from weekend rain braced for more powerful downpours today as a strong Pacific storm swept across the Southland.

The new storm was expected to deliver 1 to 3 inches along coastal plains and 3 to 6 inches in the mountains. In Orange County, weather forecasters said, rain -- likely heavy at times -- was expected to continue into Thursday, with a chance of thunderstorms and temperatures in the 60s. The rain will let up in the form of occasional showers Thursday afternoon, ending late in the day, forecaster said.

The storm “slowed quite a bit” as it came onshore Tuesday, said Stuart Seto, a specialist with the National Weather Service center in Oxnard. “That’s why it’s hitting so hard.”

In Orange County, Tuesday’s rainfall measured more than 2 inches in the Santa Ana Mountains and 0.65-inch near San Juan Capistrano, resulting in the usual rash of traffic snarls and fender benders countywide. Several fire stations began distributing sandbags to residents in anticipation of continuing rain.

County health officials also advised the public to avoid storm drain runoff and ocean water. Runoff from storm drains causes bacteria levels in the ocean water to rise to unhealthful levels for swimmers and surfers.

Authorities were concerned about flooding in some areas, including those scoured by last year’s devastating wildfires. As of 7 p.m. Tuesday, flash flood warnings had been issued in Orange, San Diego, southern San Bernardino, western Riverside and southern Santa Barbara counties. San Bernardino County officials activated the county’s telephone emergency notification system for the first time, warning residents in burned and other susceptible areas about flood danger.

Swift-water and other rescue teams were on standby throughout the region, authorities said. San Bernardino County officials hoped the storm’s slowing would put off the worst of the rains until this morning.

The potential for flooding was of less concern in Riverside County, because fire damage was not in steep terrain, said Riverside County Fire spokesman Rick Vogt.

By late Tuesday night, runoff from a burned hillside in Santa Clarita flooded the entrance to a mobile park, creating a river about 5 feet deep and 30 feet across and stranding residents of about 100 homes, authorities said.

Despite all the problems and worries, the rain did bring positive news for some areas, particularly parched forest lands where officials had posted red-flag fire warnings and even closed some parklands.

For example, in the Angeles National Forest, closed since late September because of the extreme fire danger, officials announced that the park would be reopened today after receiving 1.4 inches of rain through Monday.

“This is high rainfall for this early,” said Brad Doyle, a forecaster with the National Weather Service. “Usually we don’t get this until November or December.”