Cyclone churns off California bringing yet more storm misery

LOS ANGELES - An enormous cyclone gyrating off California's coast was dumping rain Wednesday, threatening further floods and landslides in the already sodden state.

At least 18 people are known to have died in the parade of storms that have lashed the western United States, bringing rainfall levels not seen in 150 years to some places.

Communities have been washed out, powerlines toppled and roads blocked by rockslides as an endless deluge pounds the Golden State.

On Wednesday a swathe of northern California was under a flood watch or winter weather advisory.

READ: California reels from 'endless' storm onslaught, 14 dead

"The heaviest rains are expected to impact northwestern California through the next couple of days with a few inches of rain possible," the National Weather Service warned.

That rain will come on top of weeks of downpours that have left the earth saturated, with rivers fit to burst and hillsides at risk of collapse.

California Governor Gavin Newsom, who visited weather-wrecked Capitola on Tuesday, said with a seemingly endless stream of storms coming in from the Pacific Ocean, even lesser downpours could prove problematic.

"The number of inches of rain, and the intensity doesn't tell the entire story," he told reporters.

"We're soaked, this place is soaked. And now just more modest amounts of precipitation could add as equal or greater impact in terms of the conditions on the ground."

More than 55,000 homes and businesses were without power in California on Wednesday, according to tracking site Poweroutage.us, and there have been tragedies across the state.

Winter storms are not unusual in California, which tends to get most of its annual rain over a fairly short period.

READ: State of emergency declared in winter storm-battered California

But the current systems -- which have brought more rain to San Francisco in two weeks than at any time since 1866 -- are vicious.

Scientists say global warming, which is being driven by human activity, is making weather events more extreme, with wet periods much wetter and dry periods much drier.

Despite the misery, the storms, which are expected to continue to rake California for another week, are bringing rain to a part of the country that badly needs it after more than two decades of drought.