Rain, wind begins lashing northern California as storm approaches

SAN FRANCISCO (Reuters) - Rain and high winds began lashing northern California overnight as a major winter storm that marched across the Pacific Ocean was set to pound the state on Thursday, according to the National Weather Service.

Authorities have issued flash flood, high surf and wind warnings ahead of the storm and said they feared that predicted heavy showers could lead to mudslides in wildfire-scarred foothills across the state.

Wind gusts peaking at 50 mph (80 kph) had been recorded on the Sonoma County coast north of San Francisco, the National Weather Service said early on Thursday morning.

Weather officials predicted the storm could drop as much as 4 inches (10 cm) of rain on the area, with a heavy band expected to sweep through the San Francisco region on Thursday morning.

"The fact that it looks like so much of it is going to fall in such a short period of time, that's one of the major concerns," National Weather Service meteorologist Charles Bell said.

Several area school districts, including San Francisco, Oakland and Berkeley, canceled Thursday classes due to the storm.

A winter storm that moved through Southern California last week, the first of the season, brought record-breaking amounts of rain to some communities. However, that rain was not as intense, falling over a longer period of time, National Weather Service meteorologist Mark Jackson said.

California has been in the grip of a record-shattering, multi-year drought that has forced officials to sharply reduce water supplies to farms and prompted drastic conservation measures statewide.

The current storm is expected to move into Central California on Thursday afternoon and start hitting Southern California by late Thursday.

Authorities issued advisories for residents to stay off jetties, piers and rocks along the state's coastline to avoid getting washed into the sea as heavier surf was recorded at state beaches on Wednesday afternoon.

"It's common sense. If you look out and the surf looks like a gigantic washing machine, most people know they shouldn't go in there," Jackson said.

(Additional reporting by Dan Whitcomb in Los Angeles; Editing by Crispian Balmer)