SAN FRANCISCO — A ferocious storm pounded Northern California on Thursday, pushing floodwaters over the banks of the Russian and Napa rivers, forcing hundreds of residents to flee their homes for the second time in two months and closing dozens of state highways.
About 60 miles north of San Francisco in Guerneville, where hundreds of homes were inundated during heavy rains in January, the Russian River was rising as much as a foot an hour during the day and was expected to crest at 12 feet above flood level by Thursday night.
"It has already reached flood stage," said Janice Atkinson, a spokeswoman for the Sonoma County Office of Emergency Services. "It has been highly recommended that residents in low-lying areas evacuate and move to higher ground."
Meanwhile, dozens more residents in the Ventura County seaside town of La Conchita packed up their belongings and left the hilly residential area where recent mudslides destroyed seven houses and two trailer homes.
Disaster officials issued stern warnings to residents that they could be buried beneath more mudslides, as forecasters predicted up to 2 1/2 inches of rainfall in the next 24 hours. By Thursday night, the leading edge of the storm was over La Conchita, south of Carpinteria, and it had begun to sprinkle in Los Angeles as well.
In the Napa Valley town of St. Helena, more than 300 residents took refuge in an emergency shelter when the Napa River rose to a record level of more than five feet above flood stage and water began rising around homes, a mobile home park and apartment houses.
Downriver, residents of Napa were protecting their homes and businesses with sandbags and evacuating low-lying areas in anticipation of floodwaters not equaled since 1986, when the region experienced record flooding.
Thursday's storm was so severe that the Coast Guard halted all commercial shipping traffic in and out of San Francisco Bay because of winds gusting to 45 knots and swells in the bay of 11 feet.
Coast Guard Petty Officer Jeff Murphy said this was only the second time the bay has been closed to commercial vessels since 1982. The only other time was Jan. 6, when the first of several damaging storms hit the Bay Area and caused widespread flooding.
In the Diamond Heights district of San Francisco, the gale-force winds whipped a house fire out of control, contributing to the death of one firefighter and injuring three others when they were trapped in the garage.
San Francisco authorities closed roads through Golden Gate Park because of the danger of falling trees and branches. The high winds also forced the closure of two of the four runways at San Francisco International Airport, causing delays for many travelers. Winds on top of Mt. Tamalpais across the bay in Marin County were clocked at 113 m.p.h.
The heavy rains and accompanying mudslides forced the closure of portions of 30 state highways in the region, including heavily traveled Interstate 5 north of Sacramento and U.S. 101 at the Marin-Sonoma County line. In some areas, as much as an inch of rain was falling every half hour.
In the Bay Area, a second storm was expected to hit today, with the possibility of heavy rains that could exacerbate the flooding. The Weather Service posted flash flood watches, mudslide watches and high wind watches for parts of Northern California.
"If more rain occurs, which is likely, then the flooding will be aggravated and will likely keep going until Saturday," Maxwell said. "If it is heavy rain, it could actually make the floodwaters higher than they are now."
The January floods contributed to at least 11 deaths and forced thousands of people to flee their homes, primarily when the Russian River spilled into the Guerneville area.
At the height of the disaster, the river crested at 16 feet above flood stage, inundating houses and businesses, tipping over mobile homes and sweeping away cars, boats and tons of household possessions.
Barring new rainstorms, authorities said the latest Russian River flood will crest about four feet short of the January level.
Many residents had completed repairs on their flood-damaged houses and moved back in recent weeks, only to be forced out again Thursday.
"People were getting on with their lives," said Atkinson, the emergency services spokeswoman. "Things were being put back together."
But in a dramatic repeat of the January disaster, the Sonoma County Sheriff's Department said that rescue crews in inflatable rubber boats had begun evacuating residents from their homes by midday Thursday.
"The experience with those folks is they don't get out until they have to," said Tim Duncan, executive director of the American Red Cross in Sonoma County.
Duncan said the Red Cross expected to open at least three shelters to handle evacuees in the county, including residents forced from their homes in Petaluma and Cloverdale by flooding.