California braces for 'pineapple express'

A major winter storm moved across the Pacific Ocean into Northern California on Wednesday and was expected to move south to pummel the state with torrential rainfall, hurricane-force winds and dangerous high surf over the next few days, the National Weather Service said.

The storm is expected to be one of the windiest and rainiest in five years, according to the weather service, and could also cause debris slides, especially in areas affected by this year’s intense and widespread wildfires.

"As far as serious debris flows this is probably the biggest threat we've seen so far this winter on the burn areas, just because the rainfall has the potential to be so intense in such a short period of time. That's what we've seen in the past is most conducive to debris flows," National Weather Service meteorologist Mark Jackson said.

The current storm features an “atmospheric river” according the weather service, a meteorological phenomenon that is usually about 250 to 400 miles wide and known as a “pineapple express” on the West Coast because it carries moisture from Hawaii.

Heavier that normal surf was already being seen on state beaches on Wednesday afternoon and forecasters said some local sets could hit 25 feet along the Central California coast, with 8 to 12 foot waves in Ventura, Los Angeles and Orange Counties. The Los Angeles Times reported some waves could reach 25 feet in height.

In Northern California, residents packed sandbags and crews cleared storm drains on Wednesday as many San Francisco Bay Area schools announced they would be closed on Thursday. Some low-lying areas were still cleaning up from heavy rains on Dec. 3.

The NWS has issued an array of warnings and advisories related to the storm including a high wind warning, a flash flood watch, a gale warning, a high surf advisory and a hazardous seas advisory.

“We have crews working starting tonight in 12-hour shifts,” Rachel Gordon, a spokeswoman for San Francisco’s public works agency told KFSM. “It will be all hands on deck.”

The storm is expected to hit Central California on Thursday evening and Southern California on Friday morning.

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.

Jackson said the storm would provide some small measure of relief to the state but that it would not end the drought on its own.

"Certainly these storms don't hurt," he said. "But to really make a significant dent in the drought, we need numerous storms over several months at least."

Al Jazeera with wire services