A powerful storm system will reach the Southland around noon today and rain is expected to last through Saturday, officials with the National Weather Service said.

The system, which originated in the Central Pacific, will combine with a colder system out of the Gulf of Alaska Friday and Saturday, generating heavy rain through Saturday, forecasters said. High surf and heavy winds are also expected.

“A Pacific storm system will draw a large amount of moisture across southwestern California on Thursday,” the NWS said. “This will set the stage for widespread moderate to locally heavy rainfall along and west of the mountains and into the high deserts.”

The heaviest amounts of rain will be on the coastal mountain slopes with very high snow levels, the NWS said. The warmer conditions at high elevations will also melt much of the snowpack, adding to runoff and potential flooding problems.

In the San Gabriel Mountains, a wind advisory will be in effect until 3 p.m. Thursday. NWS forecasters said southeast winds of 20-30 mph would buffet the mountains today, gusting to 45 mph, then increase to 20 to 35 mph with 55 mph gusts from Thursday morning through mid-afternoon.

“Winds this strong may down trees and power lines, causing property damage or power outages,” the NWS said. “Cross winds can make driving difficult, especially for drivers of high profile vehicles and vehicles towing trailers.”

Officials said the storm system could produce 1-2 inches of rain along the coast, 2-3 inches along coastal slopes and 3-4 inches in the mountains.

NWS meteorologist Curt Kaplan noted that this winter’s rain in the Southland is considerably more extensive than in 2018. Since Oct. 1, Long Beach has received 12.42 inches of rain, which is 168 percent of normal for this time of year. The city typically receives 12.26 inches for the whole rain year.