A slow-moving winter storm brought more than two and a half inches of rain to the Long Beach area on Wednesday and Thursday, with cool and dry weather expected over the weekend.

Intense rains poured over most of the Southland on Thursday, prompting mudslides, debris flows and flooding in some areas.

Snowfall temporarily forced the closure of Interstate 5 at the Grapevine, while a mudslide blocked traffic and trapped some vehicles on Coldwater Canyon Avenue in Studio City, and flooding forced a closure of the westbound Santa Monica (10) Freeway near the McClure Tunnel in Santa Monica.

Downpours were expected to continue through Thursday evening. As of about 4 p.m., Long Beach Airport had received about 2.63 inches of rain in a storm that began Wednesday and lasted throughout the day on Thursday.

In one of the heaviest downpours, nearly one inch of rain fell between a six-hour period from 10 a.m. to 4 p.m. on Thursday.

The National Weather Service indicated by mid-afternoon that another one-half to 1 inch could still fall across the area, winding down an unusually wet month.

“Once this is all done tonight the official NWS observation site in downtown Los Angeles will have had its third most wettest month of December on record with records going back to 1877,” according to the NWS. “The wettest December was in 1889 with 15.80 inches and the second wettest was in 2010 when 10.23 inches was recorded.”

By 10 a.m. Thursday, downtown Los Angeles had received 3.6 inches of rain over the previous 24 hours, according to the weather service. At Leo Carrillo, where campers had to be rescued from flooding, 4.5 inches had fallen, while 4 inches fell in Bel Air, 5.3 inches fell in Woodland Hills and more than 3 inches fell in Alhambra and Pasadena.

Temperatures are also expected to remain “significantly below average” across the region.

This year’s December rain totals in Long Beach are above the average of 3.57 for the month. As of Dec. 29, Long Beach has seen about 3.67 inches of rain, with the current storm likely to bring another two inches.

 

Today, city officials issued a rain advisory for recreational beaches and bays in Long Beach.

City Health Officer Anissa Davis said in a statement that people should avoid recreational swimming areas for at least three days after a rainstorm because unhealthy conditions may result from increased runoff from storm drain outlets and rivers, which eventually reach the city’s beaches.

According to NWS, clear skies are forecasted after today. The city’s advisory, however, will be extended if the rain continues.

– City News Service contributed to this report